Manon's Hazelnut Cornish Shortbread

STEP 1. TOAST AND GRIND THE HAZELNUTS
Preheat the oven to 160°C fan / 180°C / 350°F. Spread the 90 g blanched hazelnuts for the dough and the 60 g for the rim onto a baking tray. Toast for 8–10 minutes until deeply golden and fragrant, watching closely as they can go from perfect to burnt in under a minute. Cool completely. Grind the 90 g portion in a food processor to a fine meal, pulsing in short bursts so they do not turn to paste. Finely chop the 60 g portion by hand for the rim; the hand-chopped irregularity gives the finished rim its craggy texture.

STEP 2. CREAM THE BUTTER AND SUGAR
In a stand mixer with the paddle attachment, cream the softened butter with the caster sugar on medium speed for 3–4 minutes, until pale and noticeably lighter. Scrape the bowl down at least once. Aerate just enough to give the biscuit tenderness — do not whip to a fluffy sponge batter. Add the vanilla extract, if using, and the salt; mix briefly to combine.

STEP 3. BUILD THE DOUGH
Sift the plain flour and cornflour into a bowl and stir in the cooled ground hazelnuts. With the mixer on its lowest speed, add the dry mixture to the butter in two additions, mixing only until the dough just comes together. It should look like damp, buttery crumbs that clump when squeezed. Tip onto a lightly floured surface and bring together with your hands in as few strokes as possible — overworking activates gluten and steals the short. Shape into a flat disc, wrap in cling film, and chill for 30 minutes.

STEP 4. ROLL, CUT, AND CHILL AGAIN
Roll the chilled dough between two sheets of baking parchment to a thickness of 7–8 mm (1/3 inch) — thicker than most biscuits, as Cornish shortbread is substantial. Cut out 24 rounds with a 5 cm plain-edged cutter, re-rolling the offcuts once only. Transfer to two parchment-lined baking sheets, spacing 2 cm apart. Chill the trays for 15–20 minutes while the oven comes to temperature. This step keeps the biscuits cleanly circular rather than spreading.

STEP 5. BAKE
Reduce the oven to 150°C fan / 170°C / 340°F. Bake the biscuits for 15–18 minutes, rotating the trays halfway through, until they are a pale sandy gold — not brown. Cornish shortbread is deliberately pale; the flavour is buttery, not Maillard-roasted. The biscuits will be soft when they come out and firm as they cool. Transfer to a cooling rack and leave to cool completely, at least 45 minutes, before applying the chocolate rim.

STEP 6. TEMPER THE DARK CHOCOLATE
Place two-thirds of the dark chocolate in a heatproof bowl set over a pan of barely simmering water (the bowl must not touch the water). Melt gently, stirring, until it reaches 45–50°C (113–122°F). Remove from the heat, add the remaining chocolate, and stir patiently until it melts and cools to 31–32°C (88–90°F). Properly tempered chocolate will set with a clean snap and a soft sheen. A straight melt will still work but will not snap or shine in the same way.

STEP 7. RIM THE BISCUITS
Line the cooled biscuits up on a sheet of baking parchment. Pour the tempered chocolate into a small bowl. Dip the outer edge of each biscuit into the chocolate — only the rim, not the face — rotating to get a clean, even band about 4–5 mm wide. Return to the parchment. While the chocolate is still tacky, working in batches of six, sprinkle the finely chopped toasted hazelnuts around the rim so they stick; pinch any stray pieces onto the edge. A whisper of flaked sea salt on the chocolate face is optional.

STEP 8. SET AND SERVE
Leave the biscuits to set at cool room temperature for 30–45 minutes. Avoid the fridge, as tempered chocolate will bloom with condensation. For the 24-identical effect, line them up in four rows of six and inspect; any with wobbly chocolate rims can be re-dipped. Serve with strong coffee or tea.