Pre heat the oven at 180 deg C and line an 8 inch square baking pan.
In a bowl, add together the chocolate and oil and melt in a microwave or double boiler. Keep aside.
In a small bowl, mix together the coarsely ground oat flakes and cocoa powder and keep aside.
In another bowl, add the eggs and sugar and beat till pale and fluffy. I used an electric whisk.
Tip the chocolate mixture into the egg mixture and fold in with a spatula.
Add the vanilla and mix in.
Add the oats mixture and fold in till everything is just incorporated. do not over mix.
Tip the batter into the lined baking pan and smooth the top.
In a small bowl add the biscoff spread. It will be quite thick. Microwave for just a few seconds till it easily falls off a spoon. It should not be too runny.
Drop spoonfuls of the biscoff spread in blobs all over the top of the batter.
Using a knife, gently run it through the dollops of biscoff spread in a swirling motion in a back and forth manner.
Place the pan in t centre of the pre heated oven and bake for 25-30 minutes or till the top is firm and the middle is very slightly wobbly.
Remove from the pan from the oven and place on a wire rack to cool completely before cutting into squares and serving.