Preheat the oven to 160Fan/180*C and grease 8 silicone donut holes.
Add the flour, espresso and baking powder together. Now whisk in the milk, maple syrup and oil until thick and smooth. It will be a thick batter. Spoon into a piping bag.
Pipe the dough into the donut holes and smooth over the top. Press in the small pieces ofprotein balland bake for 12-13 minutes until risen and fluffy.
Allow to cool for 10 minutes in the donut holes and then cool fully on a wire rack.
Meanwhile, add 1 tbsp coconut oil to a fry pan and add the oats. Toast for 2 minutes, add 1tbsp maple syrup and stir well before stirring in the chopped protein balls. Stir and cook for another 2 minutes and remove from the heat.
Melt the chocolate and stir in the remaining 1 tbsp coconut oil and 1 tbsp maple syrup until silky and glossy.
Dip each donut into the chocolate and then sprinkle over the crumble topping. Allow to cool and store in an airtight container for 3 days.