FOR THE CAKE: – 2 cups (240g) all-purpose flour – 1 teaspoon baking powder – 1/2 teaspoon baking soda – 1/2 teaspoon salt – 1/2 cup (113g) unsalted butter, softened – 1 & 1/4 cups (250g) granulated sugar – 3 large egg – 1 teaspoon vanilla extract – 2/3 cup (150g) sour cream – 1/4 cup (59ml) milk – 3/4 cup (127g) chocolate chip FOR THE BUTTERCREAM: – 3/4 cup (170g) unsalted butter, softened – 3 cups (330g) confectioners’ sugar , sifted – 1 teaspoon vanilla extract – 1/4 teaspoon salt – 2 tablespoons heavy cream – 1/2 cup (85g) chocolate chip