Pineapple Squares

Step 1
Combine flour, sugar, baking powder, and salt in a bowl. Cut in butter using a pastry cutter or your hands until coarse crumbs form.

Step 2
Whisk milk, egg, and vanilla extract together in a small bowl. Add to flour mixture and knead until just combined, adding a little more flour if too wet or a little more milk if too dry. Divide the dough into thirds; 2/3 will be for the bottom, save 1/3 for the top.

Step 3
Roll 2/3 the dough out onto a lightly floured surface into an 11×15-inch rectangle. Place dough into the bottom of a 9×13-inch baking pan, making sure it comes at least halfway up the sides.

Step 4
Combine pineapple and sugar in a small saucepan and bring to a boil over medium heat, about 5 minutes. Meanwhile, pour reserved pineapple juice into a bowl and add cornstarch; stir until dissolved. Add to the saucepan and stir until thickened, about 5 minutes more. Remove from heat and let filling cool in the refrigerator, about 15 minutes.

Step 5
Scrape filling onto the bottom dough in the baking pan and smooth out.

Step 6
Preheat the oven to 350 degrees F (175 degrees C).

Step 7
Roll remaining 1/3 dough out onto a lightly floured surface into a 9×13-inch rectangle. Roll the dough onto the rolling pin and unroll on top of the pineapple filling, making sure edges of the dough reach the edges of the pan.

Step 8
Combine flour and sugar in a small bowl. Add vanilla extract and cut in butter until coarse crumbs form. Sprinkle streusel topping over dough.

Step 9
Bake in the preheated oven for 45 minutes. Remove from oven and let cool on a rack. Cut into 24 squares.