Muffins with blackberries

Ingredients:
5 eggs
75 g of blackberries
250 butter g
200 g of sugar
10g yeast
250 g flour

Preparation:
Put the oven to preheat to 200ºC.
In a bowl, mix the butter together with the sugar with a stick.
Beat the eggs and add little by little to the butter mixture. Sift the flour and yeast and add to the eggs.
Fill the molds 2/3 thirds of their capacity.
Put a blackberry in the center.
Bake for 15-20 minutes until golden brown.