Line a small tray with baking paper. Divide the peanut butter into 12, approx 11g per portion, and shape them into rough balls, they don't need to be perfectly neat. If it is feeling too soft to shape, chill the peanut butter in the freezer briefly to firm it up.
130 g (½ cup) thick, creamy peanut butter (NOT natural)*
Place the peanut butter balls spaced apart on the lined tray and place in the freezer for at least 30 minutes while you prepare the cookie dough.
To make the cookie dough, cream together the butter and light brown soft and caster sugars with an electric mixer until smooth.
115 g (½ cup) vegan block butter, 120 g (½ cup + 2 Tablespoons) light brown soft sugar, 50 g (¼ cup) caster or granulated sugar
Add the milk, vanilla extract, salt, baking powder, bicarbonate of soda and cocoa powder and beat again until smooth.
2 Tablespoons unsweetened non-dairy milk (I use soy), 1 teaspoon vanilla extract, ¼ teaspoon salt, ½ teaspoon baking powder, ½ teaspoon bicarbonate of soda (baking soda), 40 g (5 Tablespoons) cocoa powder
Add the flour and stir until no dry patches remain. Stir in most of the chocolate, reserving a handful to top the cookies with. Cover and place the bowl in the fridge to chill for at least 30 minutes.
160 g (1 + ⅓ cups) plain (all-purpose) flour, 140 g (5 oz/¾ cup) dark chocolate
While the dough is chilling preheat the oven to 180°C/160°C fan/350°F/gas mark 4 and line two baking sheets with baking paper.
Divide the dough into 12 even pieces (use a scale for accuracy), shape them into balls then use your thumbs to make a deep indentation in the middle.
Place one of the frozen peanut butter balls in each indentation. Use your hands to mould the cookie dough around the peanut butter, fully encasing it, there should be no peanut butter showing through.
Place the balls of dough well spaced apart on the lined baking sheets. Press a few pieces of the reserved chocolate on top of each one but do not flatten the balls.
Bake for 12-15 minutes until they are just firm around the edges but still soft in the middle (they will firm up more upon cooling).
If you prefer flatter cookies, bash the tray on the countertop a couple of times to flatten them out. Leave the cookies to cool on the tray for ten minutes before transferring to a wire rack to cool completely.