Preheat the oven to 180°c (160 fan) and line a 23x 23cm square brownie tin with baking paper.
Melt the dark chocolate and butter in a microwave in 30-second bursts, stirring each time, until fully melted and combined.
220 g Dark Chocolate, 200 g Butter
Whisk the eggs, sugars, and vanilla extract together for 3 minutes until the mixture becomes moussy and light. I use an electric whisk but if whisking by hand it will take about 5-6 minutes.
200 g Light Brown Sugar, 50 g Granulated Sugar, 3 Eggs, 2 teaspoon Vanilla Extract
Using a metal spoon, mix the cooled chocolate mixture into the egg mixture.
Fold in the flour and cocoa powder until combined
100 g Plain Flour, 45 g Cocoa Powder
Stir in the chocolate chips.
200 g White Chocolate Chips
Slice the frozen creme eggs in half using a sharp knife.
6 Cadbury Creme Eggs
Pour the brownie batter into the prepared tin and top with the halved creme eggs.
Bake in the oven for 30 minutes. It should still have a slight wobble when you take it out of the oven but if it still doesn't look set enough pop it back in for another 3-4 minutes.
Leave to cool then drizzle with melted white chocolate.
25 g White Chocolate
Leave to set fully overnight before slicing into bars.