Vanilla Cupcakes

The vanilla cupcakes' recipe (for 12 cupcakes)
***The cake batter (all ingredients are at room temperature)
180g cake flour
6g baking powder a pinch of salt
60g milk
60g yogurt
2 tsp vanilla extract
150g butter
180g sugar
3 eggs (55g each without shell)
****The vanilla buttercream
80g sugar
20g flour
175ml milk
2 tsp vanilla extract
150g butter (soft, unsalted)