Chocolate Pecan Pie Bars

Line a 9” X 13” pan with a piece of baking paper and preheat the oven to 350 °F (175 °C).
In a medium mixing bowl, using an electric hand mixer, beat together the butter and brown sugar at medium speed until fluffy and well combined.
1/2 cup (113 grams) unsalted butter, 1/4 cup (50 grams) light brown sugar
Beat in the vanilla and salt at medium speed until combined, and then beat in the flour at low speed. You’ll have crumbs and not a ball of dough.
1/2 teaspoon vanilla extract, 1/2 teaspoon salt, 1 1/4 cups (156 grams) flour
Evenly and gently put onto the bottom of the prepared pan. It’ll be quite a thin crust. You don’t need to press it down very firmly, but it shouldn’t be loose crumbs.
Bake for 13-15 minutes or until lightly browned.
Place on a cooling rack to cool for at least 10 minutes while preparing the filling.

In a large mixing bowl, stir together all filling ingredients except for the pecans, sprinkling on the cornstarch, rather than plopping it down a big clump. Do not overmix! If there are any eggy bits that aren't coming out when mixing, remove them or they’ll bake up ugly.
3/4 cup (150 grams) light brown sugar, 1 cup (320 grams) maple syrup, 3 large eggs, 1/4 cup (56 grams) unsalted butter, 1 1/2 teaspoons cornstarch, 1 teaspoon vanilla extract, 1/2 teaspoon salt
Once combined, stir in the pecans and chocolate chips.
2 1/2 cups (285 grams) pecans, 1 1/2 cups (225 grams) semi-sweet chocolate chips
Pour the filling into the partially cooled crust and bake for 28-31 minutes. The filling should appear set and not liquidy, but the whole thing kind of jiggles when you remove it from the oven. If you were to cut into them right now, it’d just look like goo. But it separates into layers as it cools and chills.
Let cool completely, about 2 hours, and then refrigerate for at least 4 more.
Refrigerate in an airtight container for up to 5 days or freeze for up to 3 months.