Prep for SuccessUse an oven thermometer. Make sure your oven's temperature is accurate by using an oven thermometer. Preheat to the temperature stated in the recipe.
Choose the right size pan. Trust the recipe. Make sure you use the size of pan it calls for to ensure accurate bake times. Looking for help? Check out the Betty Crocker Store for a full line of baking pans.
Line the baking pan. Fit a large piece of parchment paper or aluminum foil into the bottom of the pan and up over the sides, extending about 4 inches to create "handles." These handles will help you remove the finished bar cookies in the form of a slab – which makes cutting easier. Grease the paper or foil according to recipe directions. Fill with bar-cookie batter and bake as directed – placing the pan as close to the center of the oven as possible.
Tip: If you use a glass pan, decrease the oven temperature by 25 degrees.
Test for DonenessBrownies: Test for doneness by inserting a wooden toothpick two inches from the side of the pan. If it comes out clean or nearly clean, the bars are done. The center of the pan of brownies will be slightly soft.
Bar cookies: Test for doneness by inserting a wooden toothpick near the center of the pan. If it comes out clean or nearly clean, the bar cookies are done. The edges of the pan of bar cookies will be lightly browned.
Tip: Some bar cookies bake up so soft and gooey that a doneness test just isn't accurate. (Visualize bars made with caramel or marshmallow creme.) If you trust your oven thermometer, just bake bars the amount of time stated in the recipe. Remove the pan from the oven immediately to prevent over-baking.
Get Ready to CutCool them completely. Cool bar cookies and brownies completely in the pan. (Cut them while they're warm and they'll crumble.) Then either chill or freeze the bars for at least 2 hours (overnight is even better) before lifting the slab from the pan with the foil "handles." Chilling or freezing the bars will keep them from cracking as the foil is lifted.
Flip onto a cutting board. Invert the foil-lined pan of bar cookies or brownies onto a cutting board. (Ignore this step if the bar cookies or brownies include a delicate topping – or need to be frosted -- and simply place the slab, right side up, on the board.) Carefully remove the aluminum foil from the bottom of the bars. Now you're ready to cut.