Matcha & Chocolate Avocado Biscuits

STEP 1: MAKE THE BASE DOUGH

Beat the softened butter and caster sugar until pale and creamy, 2–3 minutes. Beat in the egg yolk and vanilla. Add the sifted flour and salt and mix just until a soft dough forms — don't overwork it. Tip out and bring together, then divide: weigh out roughly 60% for the matcha flesh and the remaining 40% for the chocolate stone and skin.

STEP 2: COLOUR THE DOUGHS

Into the larger (60%) portion, sift in the full quantity of matcha and knead until evenly green with no streaks. Use the bold, generous amount given — matcha mellows as it bakes, so it needs to start assertive to come through in the finished biscuit. Into the smaller portion, sift in the cocoa and knead to a uniform brown, adding a teaspoon of milk only if it feels dry. Split the chocolate dough again: about one-third for the central stone, two-thirds for the outer skin. Wrap all three and chill for 20 minutes to firm up for shaping.

STEP 3: BUILD THE AVOCADO LOG

Roll the chocolate “stone” portion into a smooth log about 2 cm (3/4 in) thick and the length of your tray — this is the avocado pit. Roll the matcha dough out into a rectangle, brush lightly with egg white, lay the stone log along one edge and wrap the matcha around it, pressing out any air, to make a fat oval log: the green flesh surrounding the stone. Finally, roll the chocolate “skin” dough thin, brush with egg white, and wrap it around the outside of the matcha log. Gently press the log into a soft teardrop/oval cross-section so each slice reads as an avocado.

STEP 4: CHILL FIRM

Wrap the finished log tightly in cling film, smoothing it round, and chill at least 1 hour (overnight is better). A properly cold log is the secret to clean, even slices that hold their picture — and to biscuits that don't spread and thin out in the oven.

STEP 5: SLICE EVENLY

Using a sharp knife and a ruler as a guide, slice the cold log into even rounds about 8 mm (1/3 in) thick. Consistent, not-too-thick slices are half the fix for a thick, under-set middle: every biscuit then bakes at the same rate and cooks through. Rotate the log a quarter-turn between cuts so it keeps its oval shape rather than flattening on one side. Lay the slices on parchment-lined trays with a little space between them.

STEP 6: BAKE THROUGH

Bake at 160°C (325°F / Gas 3) for 14–16 minutes. The moderate temperature is deliberate: matcha scorches and dulls to khaki if baked too hot, so trade a hotter, faster bake for a gentler, longer one that sets the centre without burning the green. The biscuits are done when they feel firm (not soft) in the middle and the bases are lightly golden — this fully bakes the centre the judges found under-done. If your slices are thicker, give them an extra 1–2 minutes rather than turning the oven up. Cool on the tray for 5 minutes, then transfer to a rack.