In a large bowl, cream the peanut butter, butter and sugar until light and fluffy. Beat in eggs and vanilla. Combine the flour, baking powder, salt, baking soda and cayenne; add to the creamed mixture alternately with sour cream, beating well after each addition.
Fill paper-lined muffin cups two-thirds full. Bake at 350° for 22-26 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes before removing from pans to wire racks to cool completely.
In a small bowl, cream peanut butter and cream cheese until light and fluffy. Gradually beat in the cream, confectioners' sugar and salt. Frost cupcakes. Sprinkle with peanuts, cilantro and pepper flakes. Yield: 1-1/2 dozen.