1 tablespoon unsalted butter
1/4 cup shelled and skinned peanuts, toasted (see Note)
1/4 cup cashews, toasted (see Note)
1 cup firmly packed light brown sugar
1 cup granulated sugar
1 cup water
Pinch of baking soda
To toast nuts, preheat the oven to 350 degrees. Spread the mixed nuts on a cookie sheet and toast in the oven until golden, about 15 minutes. Set aside to cool.