Brown the butter in a small saucepan over medium-low heat. Stir the butter occasionally until brown flecks appear on the bottom of the pan and the butter smells very nutty. Watch closely at this point to make sure it doesn’t burn. Remove from heat when the butter reaches a golden brown color. Transfer to a heat-proof bowl and refrigerate until it reaches a softened consistency, about 45 minutes.

While the streusel bakes, prepare the apples by coring each apple, cutting into fourths, slicing lengthwise, and then dicing into 1/4-inch pieces. In a large bowl, combine the apple pieces, lemon juice, cinnamon and salt and stir well to coat all of the apple pieces. Cover and store in the refrigerator.

To continue the cookie crust: In a large bowl, mix the flour, baking soda, salt and cinnamon until combined.

In the bowl of a stand mixer, combine the brown butter (that has returned to a “softened state in the refrigerator) with the sugar and brown sugar and cream until combined. Add the egg and vanilla and mix on medium until smooth. Slowly add the dry ingredients and mix just until incorporated. The dough should be a little crumbly.

Turn the dough out onto a Silpat-lined cookie sheet or pizza stone and roll into a 9-inch round circle. Bake in the preheated oven for 8-9 minutes. The center should still be a bit underdone. Remove and let the crust cool.

While the crust cools, mix the sauce ingredients together with a wire whisk until smooth. Spread in an even layer on the cooled crust.

Spread the apple pieces in an even layer on top of the sauce. And then top with the streusel pieces.

Refrigerate for at least 30 minutes. Slice and serve. Wrap tightly and store in the refrigerator for up to three days.