Combine the melted butter, sugar, salt, and almond extract.
Add flour.
Combine until the dough comes together. Note: if you use a paddle attachment, the dough will come together in a ball. This is okay. Proceed as normal.
Set aside approximately 2 cups of the dough (you can eyeball this).
Put the remaining dough into a well-greased 13 x 9-inch pan. Or for easier removal, line your pan with parchment or foil and grease.
Press the dough firmly in the pan.
Warm the preserves in the microwave for about 1 minute.
Spread the preserves over the crust layer.
Now it's time to add the roll of almond paste into the remaining 2 cups of shortbread dough.
Break the almond paste into large crumbles.
Using a pastry cutter, blend the almond paste with the shortbread dough. If your dough is in a lump from using a paddle attachment to mix it, the pastry cutter will break it up.
Sprinkle this crumble mixture over the preserves and press down lightly.
Bake at 325 degrees until bars are lightly browned around edges and the top begins to brown (approx. 40- 45 minutes in a glass pan or 35-40 minutes in a metal pan).
Remove from the oven.
If you didn't line your pan with parchment or foil, do this: while the cookies are still hot, loosen the edges with a knife. If you don't, the preserves will harden and stick to the sides, making them harder to cut.
Let the cookies cool completely before cutting.
Can be made ahead of time and stored in the freezer.