Brownie thumbprint cookies

Preheat the oven to 160ºC, gas mark 3. Line 2 baking trays with baking parchment. Sieve the cocoa into a large bowl, add the sugar, then whisk in the oil, vanilla and eggs. Use a wooden spoon to stir in the flour, baking powder and salt until you have a soft dough with no visible pockets of flour. Chill the dough in the fridge for 30 minutes to firm up.

Roll the chilled dough into 18 balls (about 35g each) in the palm of your hands. (The balls can be frozen at this point if you like – defrost fully before baking.) Sieve the icing sugar onto a plate and gently roll each ball in the sugar to coat. Divide between the lined trays, leaving space between them to expand, then make a deep dent in the middle of each one with your thumb. Bake for 12 minutes. While still hot, push the end of a wooden spoon into the holes to make them slightly deeper and wider. Leave to cool completely on the trays. Spoon a little of the pistachio cream, Nutella or jam into the thumbprint in each cookie. They’ll keep in an airtight container for 3-5 days.