Preheat oven to 160°C fan / 180°C conventional. Brush the melted butter into the holes of the mini bundt tin, ensuring all the grooves and edges are fully coated. Then sprinkle the flour (or cocoa powder) inside each hole and tilt the tin in all directions to lightly coat the surface. Tip the tin upside down and tap out the excess flour.
1 tablespoon Melted butter, 1 tablespoon Plain flour
In a large bowl, whisk the dry ingredients together until combined (make sure there are no clumps of sugar). Make a well in the middle.
130 grams Self raising flour, 20 grams Cocoa powder, 150 grams Light brown sugar
In a separate bowl, whisk the wet ingredients together.
150 millilitres Vegetable oil, 2 medium Eggs, 1 teaspoon Vanilla extract, 50 millilitres Milk
Pour the wet ingredients into the dry. Whisk until the mixture is smooth and combined.
Pour the mixture into a large piping bag and snip off the end. Pipe the mixture in a circular motion into each hole of the bundt tin, filling them just over halfway. You can use spoons to fill the tin instead, but piping it is quicker and easier.
Bake for 18-20 minutes until risen and golden. Leave the cakes to cool in the tin for 20 minutes, then use a knife to carefully peel the sponges away from the outside edge. Give the cakes a wiggle and when they feel loose, remove them from the tin. Pop them on a wire rack to cool completely.