• In a bowl, combine the cake flour with the baking powder, mix well and set aside
• In another bowl, beat together butter & sugar until light & fluffy. To this mixture, beat in the egg, oil, milk, and yogurt
• Fold in the flour and baking powder mixture and make sure there are no lumps
• To the batter, add tablespoons of dulce de leche and mix well
• Pour the batter in cupcake liners making sure you do not fill more than ¾th batter in each cupcake liner. Bake these at 180 degrees C for 20 mins or until an inserted skewer comes out clean
• Let cool completely and then using a nozzle or a melon baller make a hole in the center of the cupcake. Fill the cupcake center with dulce de leche

FOR THE FROSTING

• Beat the butter until light and fluffy
• Keep adding tablespoons of icing sugar a little at a time until all the sugar has been incorporated in the butter or until the buttercream frosting is of the right consistency
• Add the dulce de leche to this mixture and beat well
• Put this mixture in a piping bag and frost it onto the cupcakes
• Once frosted, swirl some dulce de leche onto the top of the cupcake to give it that complete look of a perfect cupcake