Blackberry and Hazelnut Frangipane Tart: A Gluten-Free Late-Summer Recipe
This content is for educational purposes only and does not constitute medical advice. Wild plants can be dangerous if misidentified. Never consume any wild plant unless you are completely confident in your identification. Some wild plants can interact with medications. Always consult your GP before using wild plants medicinally, particularly if you are pregnant, breastfeeding, or taking medication.
Three things to take from this recipe
- Identify hazel by its rounded, toothed leaves, downy stems, and green nuts enclosed in leafy husks — do not confuse with other shrubs.
- Both hazelnuts and blackberries contain polyphenols and fibre that researchers are studying for antioxidant and anti-inflammatory effects, but this is a nutritious food, not a treatment.
- This gluten-free tart uses ground hazelnuts and gluten-free flour, making it suitable for coeliacs and those avoiding wheat.
By late August, two of the hedgerow’s most generous offerings are ripening at the same time: blackberries darkening on the bramble and hazelnuts fattening in their leafy husks. This tart brings them together in a gluten-free frangipane that is sharp with blackberry juice, nutty with ground hazelnuts, and sturdy enough to survive a walk home in a tin.
The recipe is straightforward: a gluten-free pastry case, a hazelnut frangipane filling, and a generous layer of fresh blackberries baked through the middle. It keeps well for three days and tastes better on the second day, when the blackberry juice has soaked into the almond filling.
Identifying hazel in late August
Hazel (Corylus avellana) is a shrub or small tree common in British hedgerows and woodland edges. The leaves are rounded, doubly toothed, and softly hairy. The bark is smooth and grey-brown, and the stems are characteristically downy when young. By late August, the nuts are visible inside their modified leafy bracts — two protruding green husks that open at the tip as the nut ripens.
Hazelnuts are generally ready to harvest from late August through September. The nuts should be plump, with the husks beginning to brown and open. They can be picked green and ripened indoors in a dry, warm place, or left on the shrub until the husks fully open and the nuts drop. Always check that the nuts are firm and filled — empty or shrivelled nuts are common and can be discarded.
Safety note: Hazelnuts are tree nuts. Anyone with a known tree-nut allergy should not consume this recipe. If you are foraging, be certain of your identification — there are no common toxic lookalikes for hazel in the UK, but you should always confirm the whole plant, not just the nuts.
The science: what these foods contain
Hazelnuts are one of the richer dietary sources of polyphenols among tree nuts. A 2025 study in PMC reported that hazelnut extracts exerted anti-proliferative effects in laboratory cell models, which the authors attributed to the high content of phenolic compounds and dietary fibre. The full study is available at PMC12840033 (Turkish hazelnut extracts, 2025).
A 2024 review in PubMed examined whether hazelnut consumption affects brain health, noting that hazelnut’s profile of vitamin E, folate, and polyphenols may attenuate the risk of neurodegenerative disorders. This is promising but preliminary — it is composition and mechanistic research, not clinical proof. The full review is at PubMed 38151890 (hazelnut and brain health, 2024).
Blackberries contribute their own polyphenols to this recipe: anthocyanins (the pigments responsible for the deep purple-black colour) and ellagic acid. A 2024 study in PMC confirmed that anthocyanin-rich purple plant foods exert antioxidant and anti-inflammatory effects in laboratory settings. The full paper is at PMC12348956 (anthocyanin-rich plant foods, 2024). An earlier study on ellagic acid from blackberries, published in PubMed, highlighted its antioxidant and potential anti-inflammatory properties. The full study is at PubMed 37894909 (ellagic acid from blackberries, 2024).
The honest summary: both ingredients contain compounds that researchers find interesting, and eating a varied diet rich in polyphenols is associated with better health outcomes in observational studies. But a tart is a tart, not a treatment. The science tells us these are good foods to include; it does not tell us they cure anything.
Gluten-free blackberry and hazelnut frangipane tart
Serves: 8 | Prep time: 30 minutes | Cook time: 40 minutes | Total: 1 hour 10 minutes
Ingredients
For the gluten-free pastry:
150g gluten-free plain flour (a blend containing rice flour and tapioca works well)
75g cold butter, cubed
1 tablespoon cold water
Pinch of salt
For the hazelnut frangipane:
100g shelled hazelnuts, toasted and ground
75g butter, softened
75g caster sugar
2 eggs, at room temperature
1 teaspoon vanilla extract
1 tablespoon gluten-free plain flour
For the blackberry layer:
250g fresh blackberries, rinsed and patted dry
1 tablespoon caster sugar
1 teaspoon cornflour (cornstarch)
To finish:
A handful of whole toasted hazelnuts, roughly chopped
Icing sugar, to dust
Method
1. Make the pastry: Rub the cold butter into the gluten-free flour and salt until the mixture resembles breadcrumbs. Add the cold water and bring together into a ball. Wrap in cling film and chill for 20 minutes.
2. Line the tin: Roll the pastry out between two sheets of baking parchment (gluten-free pastry is fragile and tears easily). Press into a 23cm loose-bottomed tart tin. Trim the edges, prick the base lightly with a fork, and chill for a further 15 minutes. Preheat the oven to 180°C (160°C fan).
3. Blind bake: Line the pastry case with baking parchment and baking beans. Bake for 12 minutes, then remove the beans and parchment and bake for a further 5 minutes until the base is dry and pale golden. Set aside to cool.
4. Prepare the blackberry layer: Toss the blackberries with the caster sugar and cornflour in a small bowl. The cornflour will thicken the juice as the tart bakes, preventing a soggy base.
5. Make the frangipane: Cream the softened butter and sugar together until light and fluffy. Beat in the eggs one at a time, then fold in the ground toasted hazelnuts, vanilla, and gluten-free flour. The mixture should be soft and spreadable.
6. Assemble: Spread the frangipane evenly across the base of the cooled pastry case. Spoon the blackberries over the frangipane, pressing them gently into the surface. Scatter the chopped hazelnuts on top.
7. Bake: Bake for 35–40 minutes, or until the frangipane is golden, risen, and just set in the centre. A skewer inserted into the frangipane (not a blackberry) should come out clean.
8. Cool and serve: Allow the tart to cool in the tin for 15 minutes before removing. Dust with icing sugar and serve warm or at room temperature. It pairs well with a spoonful of crème fraîche or natural yoghurt.
Storage and notes
The tart keeps well in an airtight container at room temperature for up to three days. It also freezes well — wrap slices individually in baking parchment and foil, then freeze for up to two months. Defrost at room temperature.
If you cannot forage hazelnuts, shop-bought shelled hazelnuts work perfectly. Toast them in a dry pan for 3–4 minutes before grinding to intensify the flavour. If you cannot forage blackberries, frozen blackberries can be used — thaw and drain them first, and increase the cornflour to 2 teaspoons.
Foraging notes and UK law
Under the Wildlife and Countryside Act 1981 and the Theft Act 1968, you may collect foliage, fruit, and flowers for personal use from public rights of way and common land, provided you do not uproot the plant or harvest from protected species. Always check local bylaws, avoid nature reserves unless foraging is explicitly permitted, and never forage on private land without the landowner’s permission.
Take only what you will use, leave plenty for wildlife, and avoid picking below waist height along paths where dogs may have marked the plants. Blackberries and hazelnuts are abundant, but local over-harvesting can reduce the food available for birds and small mammals heading into autumn.
Download the free guide
The Seasonal Foraging Calendar — a month-by-month guide to what to forage, where to look, and why it matters. Save it before your next walk, and use it alongside a trusted field guide and in-person tuition.
References
Turkish hazelnut extracts exert anti-proliferative and antioxidant effects. (2025). PMC. PMC12840033
Does hazelnut consumption affect brain health and neurodegenerative risk? (2024). PubMed. PubMed 38151890
Anthocyanin-rich purple plant foods: bioavailability and health effects. (2024). PMC. PMC12348956
Ellagic acid from hull blackberries: extraction, purification, and bioactivity. (2024). PubMed. PubMed 37894909
