Preheat your oven to 180°C/350°F/Gas Mark 4. Use a muffin tin. I had two 12 hole tins and filled 16 in total. Grease each hole with a tiny bit of butter.

In a large bowl beat the sugar, butter and vanilla extract together until light and fluffy. Add the eggs one at a time, beating each one in until well combined as you go.

Add the melted dark chocolate and fold this into the mixture.

Sift in the flour, cocoa, salt and baking powder. Gently fold this into the mixture until well combined. You don’t really want to beat this in; you just want to get it absolutely combined so that there are no horrible bits of flour or cocoa left in.

Spoon into the muffin tin holes about ¾ of the way up each one. Pop into the oven and bake for around 25-30 minutes. Take out of the oven, cool for 5 minutes and then take each one out of the muffin holes and cool on wire rack completely.

When they are cool cut a hole in the top of each brownie big enough so that you can push a rolo into the centre. Do this and then “plug” the hole with the bit of brownie that you cut out.

Melt the milk chocolate and add some chopped mixed nuts into it (as much as you like, but not so much as the chocolate won’t set again.) Put about a teaspoon onto the top of each brownie and spread it over. Pop into the fridge for about 30 minutes to set. Store in a tin in a cool, dry place.