Cream butter and sugars for about 8-10 minutes until light and fluffy.
Add the vanilla extract, the oat flour and salt until combined.
Finallly stir in the chocolate chips.
In your hands roll up the dough to make lots of little balls.
Place on a baking parchment on a baking tray then rest in the freeze for at least 1 hour to firm up.
Pre-heat the oven to 150°C and line and grease a 20cm square cake tin.
Melt the chocolate slowly in a bain marie.
Meanwhile beat the butter and sugars together until light and fluffy.
Add the eggs one at a time, mixing in well. Then add the vanilla extract to thoroughly combine.
Pour in the melted chocolate and mix together.
In a separate bowl sift together the flours, cocoa powder and salt. Fold into the chocolate batter.
Pour half of the brownie batter into the tin, then dot with 3/4 of the cookie dough balls. Pour the rest of the batter over the top, smooth and then push in the remaining cookie dough balls. Bake in the oven for 25 minutes.
Remove from the oven then leave the brownies in the tin to cool.
To make the brownies easier to cut, once they are cool you could transfer the tin to the fridge for a couple of hours. Remove the brownies from the tin and then cut into 12.