- 9 tablespoons unsalted butter
- 3/4 cup powdered skim milk
- 3 large eggs, room temperature
- 1 box Duncan Hines® French Vanilla Cake mix
- 1 teaspoon vanilla extract
- 3/4 cup semisweet chocolate chips
- 2 cups toffee pieces or Heath Bar bits
- 6 tablespoons sugar
- 2 tablespoons water
- 5 tablespoons egg whites
- A pinch of salt
- 1 cup unsalted butter, cut into 1/2 inch pieces, at room temperature
- 3/4 teaspoon vanilla extract
- Approxmiately 1 cup
- Place the butter and powdered milk in a pot and cook over medium heat, stirring constantly, until the butter has separated and cooked to a hazelnut color. Remove from the heat and carefully pour into a mixing bowl. Allow the mixture to cool until warm to the touch, about 30 minutes.
- In an electric mixer fitted with a paddle attachment, combine the eggs and vanilla on low speed. Once combined, slowly pour in the warm butter and mix until thoroughly combined.
- Add the Duncan Hines French Vanilla cake mix slowly with the mixer on low until combined, about 1 minute.
- Add the chocolate chips and toffee pieces and mix until just combined.
- Using your hands, press the dough into a 9 inch x 13 inch baking pan lined with parchment paper.
- Bake in a 300°F convection oven until a toothpick inserted comes out clean, about 30 to 35 minutes. The dough will puff up but settle down after cooled.
- Once cool, remove from the pan and trim off the elevated edges. Reserve; if not using immediately, wrap tightly in plastic and store at room temperature.
- Reserving 2 tablespoons, place the rest of the sugar in a sauce pot with the water.
- Place the egg whites in an electric mixer fitted with the whisk attachment and mix on low speed. Slowly add reserved sugar and salt and mix until combined and frothy. Turn the mixer off but leave the bowl on the mixer.
- Place the sugar and water over medium high heat and stir slowly to combine. Once the mixture boils, stop stirring and insert a thermometer. When the mixture reaches 230°F, turn the mixer on medium high. Cook the sugar to 240°F and remove from heat.
- The egg whites should be at medium peak; if not, turn the mixer to the highest speed to achieve this quickly. Once medium peak is achieved, lower the speed to medium and slowly pour the sugar mixture into bowl in the area between the path of the whisk and the wall of the bowl. Once the sugar is completely added, turn the mixer to high and whisk until cool.
- Remove the whisk attachment and insert the paddle attachment. Slowly add the butter on high speed. Wait until each piece is incorporated before adding the next.
- Mix until all of the butter is added and the mixture is completely smooth.
- Cover the trimmed blondies with 2 cups of buttercream and spread into a smooth, even layer. The frosting should be about 1/4 inch thick.
- Sprinkle the chocolate shavings over top of the buttercream and lightly press them in with the palm of your hand.
- Cut the blondies into desired sized rectangles, preferably dividing the short side into thirds and the longer side into quarters.