Peanut Butter Cake with Chocolate Peanut Butter Frosting

Sift dry ingredients together in a large bowl. Add butter and milk, beat for 2 minutes at medium speed with an electric mixer. Add eggs and milk, beat for 1 minute. Add peanut butter to the batter beat at low speed until thoroughly mixed. Butter two 20 cm cake tins. Line with greaseproof paper, grease the paper, sprinkle with flour and shake out excess. Divide batter equally between the pans and bake at 180 C / 350 F / Gas 4 for 25 to 30 minutes. To ice, spread with peanut butter while the cake is still warm or use the Chocolate Peanut Butter Frosting. Melt chocolate chips and butter in a double boiler. Add icing sugar and peanut butter and beat until smooth. Chill for about 15 minutes or until frosting is of spreading consistency.