1. For thicker bars use a 9x9 inch pan and bake 25 to 30 minutes; Do not overbake for fudgy texture as carryover heat finishes the center; Swap half the chocolate chips for chopped walnuts or pecans; For extra brownie flavor add 1 tsp espresso powder to the dry ingredients; Store airtight at room temperature up to 4 days or freeze up to 2 months