I haven't tried any of the yummy sounding recipes from this thread yet -- just wanted to add one of my personal favorites (it always disappears quick at a pot luck!)....not for those watching their fat calories but.....
I got this recipe out of The Cake Mix Doctor cook book by Anne Byrn and have slightly modified it for my family's tastes.
Peanut Butter Chocolate Bars
1 pkg. plain yellow cake mix
1 cup peanut butter (original recipe calls for smooth but I've used chunky and it's still good!)
1 stick butter, melted
2 large eggs
12 pkg. semisweet chocolate chips
1 (14 oz.) can sweetened condensed milk
2 tablespoons butter
2 teaspoons vanilla
Place a rack in the center of the oven and preheat the oven to 325 degrees F. Set aside an ungreased 13x9 inch baking pan.
Place the cake mix, peanut butter, melted butter, and eggs in a large mixing bowl. Blend with an electric mixer on low speed for 1 minute. Stop the machine and scrape down the sides of the bowl with a rubber spatula. The mixture will be thick. Reserve 1 1/2 cups of the mixture for the topping. Press the remaining crust mixture evenly over the bottom of the pan so that it reaches all sides. Set aside.
For the filling, place the chocolate chips, condensed milk and 2 tablespoons butter in a medium sized heavy saucepan over low heat. Stir and cook until the chocolate is melted and the mixture is well combined. Remove the pan from the heat and stir in the vanilla. Pour the chocolate mixture over the crust, and spread it evenly to the sides of the pan. Using your fingers, crumble the reserved crust and scatter it evenly over the chocolate.
Bake the cookies until they are light brown, 20 to 25 minutes. Remove the pan from the oven and place it on a wire rack to cool for 30 min. Cut into bars. Store at room temp. for up to 3 days (good luck with that!), in the fridge for up to a week or freeze them, wrapped in foil, for up to 6 months. Thaw overnight in the fridge before serving.