Preheat oven to 350F. Grease a 9x13-inch baking pan. Set aside.
In a large bowl, whisk together the flour, sugar, and salt.
Cut in the butter until it forms coarse crumbs.
Pour into prepared baking pan and press in.
Bake for about 15 minutes, or until the edges are just beginning to turn light golden brown.
In a large mixing bowl, whisk the milk, egg, and vanilla together until well-combined.
Add the toffee bits and chopped pecans.
Pour the filling over the crust.
Return to the oven and bake for about 22-26 minutes, or until golden brown.
Let cool to room temperature.
Chill until firm.
Flour: To help keep the crust light and flaky, you don't want to pack in too much flour. To properly measure the flour either weigh the flour or stir or sift the flour to break it up, lightly spoon into the measuring cup, and level.
Salt: A pinch of salt is about 1/8 teaspoon of salt.
Butter: I use salted butter in this recipe. Also, it's important to use cold, straight from the fridge butter. This helps to make the crust flaky.
Sweetened condensed milk: Regular or fat-free sweetened condensed milk will work. Just be sure not to use evaporated milk.
Toffee bits: I use the Heath Bits o'Brickle English Toffee Baking Bits. They are just plain toffee and do not have chocolate on them.