These are a snap to bake, cut, and wrap the day before your next beach trip. Refrigerate overnight and they’ll travel well.
Preheat oven to 350 degrees F and grease an 8x8- or 9x9-inch pan. Cream the butter, brown sugar, and peanut butter until smooth. Beat in the eggs and vanilla. In a separate bowl, sift flour, baking powder, salt, and cinnamon. Add dry ingredients to the creamed mixture along with peanuts and chocolate chips. Stir until smooth. Scrape batter into pan and smooth with a fork. Bake for 30 to 35 minutes; the smaller pan will take longer. Cool thoroughly in the pan on a rack before slicing.