Preheat oven to 360 degrees. Arrange graham crackers in a non-stick rimmed cookie pan. Trim extra cookies to fit, if needed.
Melt butter in a saucepan and stir in sugar. Bring to a boil over medium heat, stirring quickly. After 2-3 minutes, the mixture will lighten, become foamy, and then get smoother in texture. Stir in pecans* and remove from heat. Pour mixture over graham crackers and distribute evenly with a spoon.
Bake for 11 minutes at 360˚, then remove the pan from the oven and let the cookies cool 2-3 minutes. Remove the cookies and place on parchment paper (not waxed paper), cutting them in half again before they harden. Cool completely before storing…if there are any left!
*Or chocolate chips. Stir them in briskly to smooth the mixture.