In a large mixing bowl stir together flour, brown sugar, baking powder, baking soda, and salt. Add milk, peanut butter, eggs and butter. Beat at low speed until mixed. Then beat on medium speed for one minute, scraping the sides of the bowl constantly.
Spread about two-thirds of the batter into a greased 13x9x2-inch baking pan. Stir jelly and spoon over batter. Drop remaining batter in small mounds on top of the jelly. Sprinkle with Crumb Topping.
Crumb Topping: In a small mixing bowl stir together 1/2 cup packed brown sugar and 1/2 cup flour. Cut in 1/4 cup peanut butter and 3 tablespoons butter until crumbly.
Bake in a 350 F oven for 30 - 35 minutes or until golden brown. Serve warm.