Whisky Peach Upside-Down Cake

INGREDIENTS

3 oz

unsalted butter, cut into ½-inch cubes

1 cup

firmly packed dark brown sugar

2 tbsp

good quality whisky or bourbon

1 lb

fresh peaches, cut into ½-inch slices (or frozen slices peaches, defrosted on paper towels)

3/4 cup

cake flour

3/4 cup

all-purpose flour

1 1/2 tsp

baking powder

1/2 tsp

baking soda

1/2 tsp

kosher salt

3 oz

unsalted butter, room temperature

1 cup

granulated sugar

large egg yolks, plus 2 large egg whites, divided

3 tbsp

vegetable or canola oil

1 tsp

pure vanilla extract

1/4 tsp

almond extract

3/4 cup

buttermilk (or regular milk, as I used)

2 tbsp

good quality whisky or bourbon

1/2 tsp

cream or tartar