Chocolate and vanilla pinwheel biscuits

Read the full method, check the stated equipment and prepare every listed ingredient. Keep dough, filling, wash, topping and handling groups separate. Weigh edible parts as described in the ingredient list.

Beat dough butter and caster sugar for 2 minutes, add egg and vanilla, then divide evenly between bowls.

Mix vanilla-dough flour and a share of salt into the vanilla bowl. Mix chocolate-dough flour, cocoa and remaining salt into the chocolate bowl. Gather gently without prolonged kneading.

Chill for 30 minutes.

Roll each between parchment to an equal 20 × 25 cm rectangle, about 4–5 mm thick. Peel top papers away, lay chocolate dough over vanilla dough and press lightly.

Roll from a 25 cm edge into a close log using paper for support. Wrap.

Chill for at least 1 hour in total until firm enough to slice cleanly.

Heat the oven to 160°C fan.

Allow about 15 minutes of heating in total and check that the oven has reached 160°C fan.

Keep chilling until firm.

Slice into 7–8 mm rounds and arrange on lined trays with 3 cm gaps. Rechill if slicing squashes the spiral.

Check the oven has reached the stated setting and carefully put in the prepared tray or tin.

Bake at 180°C conventional / 160°C fan for 12–15 minutes, until the edges are set and lightly golden; use the recipe’s centre cue.

Take the bake out of the oven and set it on a heatproof surface.

Leave on the tray for 5 minutes to firm.

Transfer gently to a rack.

Cool fully on a rack; allow about 20 minutes.