Spoon the Biscoff spread into a coffee mug and soften in the microwave for 10 seconds.
3 tablespoon Biscoff Spread
Place all of the other ingredients into the mug.
4 tablespoon Plain Flour, 3 tablespoon Caster Sugar, ¼ teaspoon Baking Powder, 1 Egg, 3 tablespoon Milk, 3 tablespoon Vegetable Oil
Use a small whisk or fork to mix everything together. Wipe down the inside of the mug with a paper towel.
Microwave for 60 seconds then for 30 second bursts at a time. My mug cake was ready after 2 minutes (900 watt on full power).
If you would like to add the optional topping, spoon one tablespoon of Biscoff spread on top of the warm sponge and let it melt in, before sprinkling over the crushed biscoff crumbs.
1 tablespoon Biscoff Spread, 1 Biscoff Biscuit