Prepare the Pan: Preheat the oven to 350°F. Line an 8×8-inch baking pan with parchment paper, leaving some overhang on the sides for easy removal.
Make the Shortbread Crust: Weigh 150 g of soft white wheat berries and mill them into fresh flour. In a medium mixing bowl, combine the freshly milled flour, granulated sugar, and salt. Add the melted butter and stir until a soft, crumbly dough forms.
Bake the Crust: Transfer the dough to the prepared baking pan and press firmly and evenly into the bottom. Bake at 350°F for 15–20 minutes, or until the crust is set and the edges begin to turn lightly golden. While the crust is baking, prepare the pecan pie topping.
Make the Pecan Pie Topping: While the shortbread crust bakes, weigh 25 g of soft white wheat berries and mill them into fresh flour. In a medium mixing bowl, combine the eggs, maple syrup, brown sugar, melted butter, vanilla extract, salt, and freshly milled flour. Mix well until fully combined. Add the chopped pecans and stir until evenly distributed throughout the filling.
Assemble and Bake: Pour the pecan pie filling over the warm shortbread crust and spread evenly across the pan. Return to the oven and bake at 350°F for 25–30 minutes, or until the topping is puffed and dry on top.
Cool and Slice: Place the pan on a wire rack and let the pecan pie bars cool completely at room temperature, then chill in the refrigerator for 30-60 minutes to help the filling firm up before slicing. Once chilled, use the parchment paper overhang to lift the bars out of the pan and cut into squares.