How to Make It
Preheat the oven to 350° and spray an 8-inch square baking pan with vegetable oil spray. In a small bowl, whisk the flour with the baking powder, salt and baking soda.
In a large bowl, using a handheld electric mixer, beat the butter with the brown sugar at medium speed until fluffy, about 1 minute. Beat in the egg and vanilla. Using a wooden spoon stir in the dry ingredients until combined. Fold in the butterscotch chips and pecans.
Scrape the batter into the prepared pan, smoothing the top. Sprinkle with sea salt and bake for 35 minutes, until the top is shiny and golden brown. Let the blondies cool in the pan, then invert onto a plate or cutting board. Invert again, then cut into squares and serve.