Preheat oven to 350˚F. Line an 8-inch square baking pan with a sheet of parchment paper, leaving a 2-inch overhang. (This will help with removing the baked blondies.)
In a large mixing bowl, whisk butter, sugar, peanut butter and honey. (Read Grant's pro tip for measuring sticky ingredients!) Whisk in eggs until well combined. Using a large rubber spatula, fold in the flour, salt and baking powder. Pour batter into baking pan and spread into a flat layer. Sprinkle chopped nuts on top and bake until edges start to become golden brown, 20-25 minutes. Let cool, then remove blondies from the pan and cut into 16 squares.