For the Blondies:

1. Preheat the oven to 350°F. Line an 8 x 8-inch baking pan with parchment paper and spritz with nonstick cooking spray.
2. Melt the butter in a small skillet over medium heat. Reduce the heat to low and stirring or swirling the pan frequently, cook the butter until the solids have lightly browned and the butter smells nutty. Remove from heat and allow to cool for a few minutes.
3. Add the cooled butter to a large bowl and stir in the dark brown sugar, whiskey, and vanilla. Mix well to combine and then stir in the egg and egg yolk.
4. Stir in the flour, baking powder, and salt and mix until a dough forms. Fold in the chocolate.
5. Press the dough into the prepared pan and bake for 20-25 minutes or until the edges are set and golden and the center is no longer gooey. Cool the blondies completely before topping with the glaze.

For the Whiskey Glaze:

1. In a bowl, whisk together the whiskey, softened butter, and powdered sugar until smooth and creamy. Add more powdered sugar, as needed, until a thick and spreadable consistency is achieved.
2. Sometimes, depending on the weather that day or the brand of powdered sugar I am using, I will need to add a splash of milk to the glaze to get it the right consistency. Start with a teaspoon and add more if you need to.
3. Spread the glaze evenly over the cooled blondies. If preferred, you can sprinkle the glaze with a little bit of flaky sea salt.
4. Allow the glaze to set for at least 30 minutes before slicing into bars. I like to transfer the pan to the fridge so the glaze really firms up. This makes it easy to slice into neat bars.