First, make the butterscotch. In a medium saucepan, melt the butter over medium-low heat. Add in the dark brown sugar and flakey sea salt. Stir, with a wooden spoon or rubber spatula, until the sugar and salt have dissolved and everything has come together--about 2-3 minutes. Stir in the cream and vanilla and bring to a low boil, stirring occasionally. Cook until thick and syrup-y--about 5 minutes. Stir in the bourbon and let the butterscotch bubble for 2 more minutes. Pour the butterscotch into a heat proof bowl and let cool while you prepare the blondies.

Preheat the oven to 350 degrees Fahrenheit. Grease and line an 8"x8" square pan.

In a small mixing bowl, whisk together the flour, baking powder and sea salt. In a large mixing bowl, whisk together the melted butter, light brown sugar, eggs and vanilla. Add the dry ingredients into the wet and stir until just combined. Stir in the chocolate chunks.

Pour the mixture into the prepared pan, making sure that you smoosh it into the corners and even it out. Drizzle thick dollops of butterscotch over the top of the batter. Using the handle of a spoon, or offset spatula, swirl the butterscotch around. 

Bake for 20-24 minutes. They're ready when the edges are set and the center is still slightly moist when you poke it with a toothpick. Remove from oven and allow to cool. Serve at room temperature or still slightly warm!