Preheat oven, butter pans:

Set oven to 350°F (175°C). Butter two 6-hole donut pans.

Whisk wet ingredients:

Combine superfine sugar, milk, vegetable oil, and eggs in a bowl; whisk until blended.

Sift and whisk batter:

Sift in self-rising flour and cocoa powder; whisk to a smooth batter.

Portion batter into pans:

Portion batter into the donut pans. For precision, pipe batter from a pastry bag or use a spoon.

Bake and cool donuts:

Bake for 12 minutes. Loosen donuts with a spoon and transfer to a wire rack to cool.

Melt dark chocolate:

Microwave dark chocolate in a bowl in 30-second intervals, stirring between each, then in 10-second intervals until fully melted.

Dip donuts in chocolate:

Set donuts on a rack above a baking sheet. Submerge the top half of each donut in melted chocolate and place back on the rack.

Add toppings:

Immediately sprinkle crushed Flake bars over the wet chocolate. Press 3 mini eggs into the center of each donut.

Store leftovers:

Keep leftovers in a sealed container; eat within 3 days.