Cut the avocado in half, remove the core. Remove the flesh from the skin with a spoon and puree with 1 tsp lemon juice.
Roughly chop the almonds. Knead 50 g sugar, 50 g butter, 75 g flour and almonds into crumbles. Mix 100 g butter, 100 g sugar, salt and vanilla sugar with the whisk of the hand mixer until creamy.
Stir in the eggs one by one. Mix 150 g flour and baking powder and stir in alternately with milk and avocado. Line recesses of a muffin tray (12 recesses) with paper cups. Spread the dough evenly into the cups.
Spread the crumbles on the dough and bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 25 minutes. Remove and let cool off.
Sift icing sugar and mix with 1 teaspoon lemon juice. Spread the icing on the muffins with a spoon.