<<Disclaimer: Verify this information before applying it to your situation.>> Several hours after the brownies came out of the often, they firmed up--even in the middle of a thunder storm here in NY. So, cornstarch may work yet, but the pan should be lined in wax paper or parchment paper for easy removal. Here is my recipe: Preheat oven to 350 Cream together 2 sticks butter with 2 cups sugar until light. Add 4 eggs, one at a time, beating until light. Add 1 teas vanilla, 2 teas almond extract (gf, of course). Beat in 2 tablespoons finelly ground goffee ( or instant) and 1/4 teas cloves. In another bowl coming 1 cup flour (your choice), 1 teas baking soda and a pinch of salt. Add to egg mixture. Blend but do not overbeat, or it will become tough. Add 1 small pkg chocolate chips (or more if you like) and 1 cup chopped nuts. Pour into 2 8" cake pans that have been buttered and covered with wax or parchment paper. Bake about 35 minutes or until test done. Cool in pan 10 minutes. Remove from pan and let cool completely before cutting into squares. (Note: It took longer to bake with the cornstarch than usual) Note the coffee grinds and cloves. That is an old baker's trick--it makes the chocolate seem richer and adds more flavor. Ann