Step 1

Preheat oven to 160’C (325’F)

Step 2

Beat butter until soft.  Add sugar and vanilla with the mixer on high speed until pale and fluffy.  Reduce speed and add the flour, cocoa and salt.

Step 3

Divide dough into 4cm (1,5 inch) balls and press into an irregular stone shape using the palm of your hand. Transfer onto parchment paper for baking.

Step 4

Dust food-safe plastic insects with flour to coat, press into dough to make fossil impressions. Chill dough for 20 minutes.

Step 5

Bake until golden brown and firm in centre, 25-28 minutes. Transfer cookies onto a wire rack to cool.