Preheat the oven to 180C/350F and grease and line an 8x8 inch square pan.

Break up the chocolate roughly and place in a heatproof bowl with the butter. Microwave in 20 second increments, stirring in between each, until all the chocolate is melted. Stir for at least 20 seconds as the chocolate will continue to melt.

Alternatively, place the heatproof bowl on top of a saucepan of simmering water and stir until melted. Leave to one side to cool.

Place sugar, eggs, vanilla and peppermint extracts into a large bowl and whisk until well combined, smooth and slightly bubbly.

Place flour, cocoa powder, baking powder, salt and crushed Oreo's into a medium sized bowl and stir until all of the Oreo's are coated in flour.

Pour the slightly cooled melted chocolate mixture into the egg and sugar mix and whisk until thick and smooth.

Tip the flour and Oreo mixture into the chocolate mixture and switch to a wooden spoon/spatula to gently fold in the flour mixture. Mix until you can't see any lumps of flour, but don't beat.

Tip the mixture into your lined pan and smooth until level with the back of a spoon/spatula. Break up the 4 extra Mint Oreo's by hand and sprinkle on top of the brownie mix. Press into the mixture lightly.

Place in the oven for 32-35 minutes until risen and puffy looking, the top will also be lighter in colour than it was when you put it in. If you stick a skewer into the edges it will come out clean, but if you put it into the centre, there should be a few crumbs on it, this is perfect. If the skewer is clean in the centre the brownies are over done.

Leave to cool in the pan completely, before transferring to a cutting board to slice into 9-12 bars.

Mint Oreo Brownies will keep in an airtight container, at room temperature for 5 days.