Homemade Twix Bars
From Chef Lesli Sommerdorf for Harmons
1/2 cup unsalted butter, at room temperature
1/2 cup sugar
1 teaspoon vanilla extract
1 cup unbleached all-purpose flour
1/4 cup sugar
4 tablespoons unsalted butter, softened
1 (14-ounce) can sweetened condensed milk
12 ounces semisweet chocolate, chopped
Coarse sea salt for sprinkling, optional
Preheat the oven to 350 degrees and line an 8- by 8-inch baking pan with parchment paper.
To make the shortbread, in the bowl of a stand mixer fitted with the paddle attachment, add the butter and sugar and cream until blended and fluffy. Add the egg and vanilla, and mix until combined. Slowly add the flour until just barely incorporated. Lightly flour the fingers and press the dough into the prepared pan. Bake until the shortbread is golden brown, 30-40 minutes. Let cool.
In a heavy-bottomed saucepan over medium heat, melt the sugar and butter. Once melted, add the sweetened condensed milk. Increase the heat to medium-high and bring to a boil. Reduce the heat to medium-low and, stirring constantly, cook until the mixture thickens and turns light brown, about 5 minutes. Pour over the shortbread and let cool completely. Lift the shortbread out of the pan and place on a cutting board. Using a long, sharp knife, slice the caramel-topped shortbread into long, thin slices. Place the slices on a cooling rack with a rimmed baking sheet underneath.
Over a double boiler, melt the chocolate. Slowly pour it over the slices of caramel-topped shortbread, using an offset spatula, if needed, to spread evenly across the top and sides. Sprinkle with sea salt, if using, and let the chocolate harden.