Stir the flour and sugar together. Cut in 2 tablespoons butter with a pastry blender or two forks or knives until it looks like crumbly sand. Press into a 8-inch square baking pan.
Bake in preheated oven for 12 minutes.
Meanwhile, make the topping: Melt the 6 tablespoons butter with the brown sugar and maple syrup in a medium saucepan over medium heat. Whisk together until sugar dissolves. Stir in vanilla and milk. Continue to whisk until the mixture slightly thickens {about 2-3 minutes}.
Stir in pecans, and remove from heat. Make sure the pecans are completely coated with the sugar mixture. Pour the pecans and sugar mixture over the baked shortbread crust.
Put in the oven and bake 10-12 minutes, until bubbly and slightly browned around the edges.
Let cool for about 20-30 minutes, then carefully flip out of pan onto a plate to cut into 12 bars. Enjoy!