The short answer here is yes - Reese's peanut butter cake is essentially just chocolate and peanut butter cake. You can make the cake layers, buttercream and ganache in this recipe without needing any Reese's cups. The cake will still be decadent and full of chocolate peanut butter flavour. You can also use any peanut butter chocolate candies to fill and top the cake in place of Reese's brand.