Breana Lai Killeen, M.P.H., RD, is a food editor, recipe developer, farmer and dietitian who has worked in all facets of the food world. She has with more than 20 years of experience cooking ...

Peggy Cullen, the owner of Lucky Star Sweets, fills her tender chocolate cupcakes with a creamy, salty peanut butter mixture; then she dips the tops twice in a rich, silky chocolate ganache frosting.

Pour batter into cupcake liners, filling halfway. Bake until the cake springs back to the touch and then set aside to cool. For the Chocolate Buttercream: Using a stand mixer, beat the butter on ...