Butterscotch Cake with Homemade Caramel Icing

Preheat your oven to 350°F / 175°C. Grease and flour (or parchment-line) two 9-inch round cake pans. In a large bowl, cream ½ cup softened butter and 2 cups brown sugar with an electric mixer until fluffy. Beat in 1 tsp vanilla and 2 eggs, one at a time, on low speed until combined.

In a separate bowl, sift together 2 cups flour, 1 tsp baking soda, 1 tsp baking powder, and ½ tsp salt. Alternately add the flour mixture and 1 cup buttermilk to the creamed butter base on low speed in 3 batches (beginning and ending with flour). Scrape down the bowl by hand.

Divide batter evenly between prepared pans. Bake at 350°F / 175°C for 25 to 30 minutes until a toothpick inserted in the center comes out clean. Cool in pans for 10 minutes, then transfer to a wire rack to cool completely.

In a small saucepan, whisk 1½ cups brown sugar, 1 tbsp flour, ¼ cup butter, and ¼ cup milk. Bring to a boil over medium heat, stirring frequently. Boil continuously for 1 full minute (or until a candy thermometer reads 238°F / 114°C).

Remove saucepan from heat immediately. Stir in 1 tsp vanilla and the remaining 2 tbsp butter. Let cool slightly, giving it an occasional vigorous stir, until warm to the touch (not hot) and thickened to a spreadable glaze.

Spread the warm caramel icing rapidly over the cooled cake layers before it sets. Allow the thin glaze coating to set completely into a soft shell before slicing.