For the vanilla cupcakes with buttercream, first bake the cupcakes.
Preheat the oven to 200 degrees. Line a muffin tin for 12 cupcakes with paper cups. Mix the flour with the vanilla pulp, baking powder and salt.
In a mixing bowl, beat the egg with the oil and sugar until foamy and add the milk. Then fold in the flour mixture. Pour the batter into the molds and bake the cupcakes at 200 degrees for about 20 to 25 minutes.
Then let the cupcakes cool and in the meantime prepare the buttercream. To do this, cook a vanilla custard with the custard powder according to the package with the milk and sugar and let it cool while stirring (no skin should form).
Beat the butter with the powdered sugar until fluffy and stir in the vanilla pudding. Put the cream in the refrigerator for about 30 minutes. After cooling, fill the cream into a piping bag and spread it on the vanilla cupcakes.