Preheat your oven to 180°C / 160°C Fan / Gas 4 and line and grease an 8" / 20 cm square baking tin. Put the butter into a large bowl or jug. Melt it in the microwave in 10 seconds bursts. Continue until the butter is melted but not hot. 115 g butter
Next, add the sugar. Stir it in so that it is well combined with the butter.
210 g light soft brown sugar
Now add the egg and vanilla extract. Stir in well.
1 large egg, 1 tsp vanilla extract
Add the cocoa powder, sifting it through a sieve to remove any lumps.
45 g cocoa powder
Next, add the flour, together with any other dry ingredients (baking powder and salt if using). Fold in to create a smooth, glossy batter.
55 g plain flour, 1 tsp baking powder, 1 pinch salt
Transfer the batter to the prepared baking tray. Smooth the surface, pushing the batter into the corners of the pan. Bake for 20–23 minutes.
While the batter is baking, cut 8 creme eggs neatly in half. There is generally a line down the shell where the chocolate was sandwiched together and this is where you should split the eggs.
8 mini creme eggs
Remove the almost cooked brownie from the oven. Now press the egg pieces into the top, fondant side up, laying them out in a 4 x 4 grid. Return to the oven for a further 5–8minutes. Allow your creme egg brownies to cool and firm up for at least 20 minutes on a wire rack before cutting. The centre will carry on cooking as it cools.
Finally, when the bake is cool, cut your creme egg Easter brownies into squares, ready to serve. I find a 4 x 4 grid of 16 pieces is perfect.