Combine the flour and 75g light brown muscovado sugar in a mixer until well combined.
Mix in the softened butter until a dough has formed.
Press into a lined 20x20cm baking dish, and prick with a fork. If you don't have an 20x20cm dish you can use any rectangular dish. You may just have to make more shortbread, but that's never a bad thing!
Bake the shortbread in the preheated oven for about 20-30 minutes (depending on the amount of shortbread you make). It should look puffy and golden brown when done.
While the shortbread is baking, beat the egg in a mixing bowl along with 75g light brown muscovado sugar, maple syrup, and pecans.
Pour the pecan mixture over the hot shortbread and return to the oven. Continue baking until firmed, about 20-25 minutes. Remove from the oven, and immediately run a knife around the edges to prevent sticking if the mixture has got past the baking parchment. Cool completely, then cut how ever you like. ENJOY!