Get all the buttery, nutty deliciousness of English toffee in a bar cookie, without having to actually getting out the candy thermometer to make English toffee with these Heath Bar Blondies! Especially perfect if you have leftover Heath Bars from Halloween!
Preheat oven to 350. Grease an 8x8-inch square baking pan.
Into a large mixing bowl, sift together: 1 cup all-purpose flour, ½ teaspoon baking powder, ⅛ teaspoon baking soda, and ½ teaspoon salt.
In a large bowl, beat together 1 cup brown sugar with 1 stick melted butter. Add 1 large egg and ½ teaspoon vanilla.
Set aside a small handful of the 1 cup of chopped Heath bars. Stir the flour mixture into the butter mixture along with chopped Heath bars. Scrape batter into pan, make sure to spread the batter out evenly to the sides and corners. Smooth the top. Add reserved chopped Heath bars and flaky sea salt to top if using.
Bake for 20 to 25 minutes. Let cool (if you have the patience) before cutting into squares.