Preheat the oven to 350 degrees.
Prepare a ceramic or tin 9x9 square baking pan by buttering the bottom and adding parchment paper. Let the sides overhang so the bars can be easily removed. You can also use a 13x9 baking dish.
Beat the butter and granulated sugar in a mixing bowl at medium speed.
Add in the vanilla and beat.
Next, add the flour, salt, and baking powder and slowly mix until incorporated, forming a dough.
Divide the dough in half and place one half in the refrigerator and evenly press the other half into the bottom of the baking dish.
Refrigerate the pressed dough in the baking dish for 30 minutes too.
Bake the dough for 15-20 minutes, then remove.
Spread 12 ounces of raspberry preserves (or any preserves you want!) over the baked crust and then crumble the other half of the dough over the preserves.
Add then crumble the other half of the dough over the preserves.
Bake for another 25 minutes. May need more time, so check to make sure the top is a golden brown.
Remove from the oven and let them cool, then dust powdered sugar over the top.
Add a sprinkle of sea salt if you like! Cut them into squares and enjoy!