Chocolate Cupcakes with Salted Dulce de Leche Filling and Salted Chocolate Buttercream

INGREDIENTS

Chocolate Cupcakes:

1 cup

unsweetened cocoa powder

1 1/2 cups

hot water

2 1/2 cups

flour

1 1/4 cups

sugar

1 1/2 tsp

baking powder

1 tsp

baking soda

1/4 tsp

salt

eggs (room temperature)

3/4 cup

vegetable oil

1/2 cup

sour cream

2 tsp

vanilla extract

Filling:

About 3/4 of 13.4 oz can of dulce de leche

About 2 Tbsp coarse salt (for filling and frosting)

Chocolate Buttercream:

16 oz

butter (room temperature)

2 cups

powder sugar

egg yolks

5 oz

dark semi-sweet chocolate (melted and cooled a little)