In one bowl, add flour, baking powder, cinnamon and salt. In another bowl, cream together butter, peanut butter and sugar, before adding eggs. Mix well together and then add in two batches the dry ingredients alternately with milk and vanilla. Just mix until combined before adding raisins.
Spoon into muffin pans and bake until lightly browned and a toothpick comes out clean - about 15 - 18 minutes.