Preheat the oven to 350°F and line a 8”x5” baking dish with parchment paper.

In a medium mixing bowl, using a hand mixer, beat together the softened butter, brown sugar, and vanilla. Add in the salt and flour and mix on low until completely combined. The dough will be crumbly but soft.

Press it into the bottom of the pan until it’s an even, smooth layer, then dock the dough (poke it with a fork all over to allow steam to escape.) Bake it for 15 minutes, then remove from the oven.

While it bakes, peel and slice the apples. Stir in the 1/4 cup of flour, 6 Tbsp. white sugar, cinnamon, and nutmeg.

For the topping, mix together the 1/2 cup of flour, brown & white sugars, cinnamon, and salt. Pour in the melted butter and stir until everything is completely mixed—it will be crumbly.

Gently press the apples in an even layer into the shortbread crust. Sprinkle the topping over it, then return to the oven and bake for 30-35 minutes, or until the topping is browned around the edges.

For the glaze drizzle, mix together the powdered sugar, vanilla and 2 tsp. of milk. Continue adding milk by the 1/2 tsp. until the glaze is runny enough drip off the end of a spoon. Place the glaze into a small zippered plastic bag and snip off a small corner. Squeeze it over the bars in whatever pattern you would like.

Allow the bars to cool completely before cutting or the will end up falling apart. To cut, lift them from the pan, using the parchment paper. Cut into 8 bars if your pan is rectangular, or 9 bars if your pan is square.