Butterscotch blondies

Spray an 8 by 8 inch pan with cooking spray and line with parchment; line a rimmed baking sheet with a silicone mat or parchment.

In a saucepan combine dark brown sugar, a little water, a little kosher salt, two teaspoons of vanilla paste and seven tablespoons of unsalted butter.

Cook, stirring with a heatproof spatula, to 260 on an instant-read thermometer, so it can be sliced but is not hard candy.

Turn out onto the lined baking sheet to set, then freeze until firm enough to cut.

Clean the saucepan and brown twelve tablespoons of unsalted butter, lowering the heat once it starts to brown and pulling it before it burns; scrape into a bowl.

Stir in two ice cubes until melted, to restore water and cool the butter to a little warmer than room temperature.

Whisk together the flour, kosher salt and three quarters of a teaspoon of baking soda.

Whisk the light brown sugar into the butter until well combined.

Add the cold eggs one at a time, whisking to emulsify to a satiny texture, then the tablespoon of vanilla extract.

Add the dry ingredients and whisk until incorporated; rest the batter about five minutes to firm up.

Break the cold butterscotch into pieces; fold two thirds into the batter and keep one third for the top.

Spread the batter in the pan, stud the reserved pieces over the surface and sprinkle with flaky sea salt.

Bake at 350F on a center rack, said as about 25 minutes, though they took closer to 40, until golden brown, wrinkly at the corners, puffed and just firm in the center.

Lift out of the pan and cool on a rack; slice with a serrated knife into 16 squares.