Prepare the Crumb Crust and Topping:

1. Preheat the oven to 375ºF and place oven racks in the lowest and middle parts of the oven. Butter or oil an 8-inch square (or similar size) baking dish. Cut a strip of parchment to fit inside the dish with ends long enough to hang over the edges. Line the baking dish with the parchment and set aside.
2. In a medium bowl, whisk together the melted butter, granulated sugar, brown sugar, baking powder, vanilla, and salt . Stir in the flour until just combined.
3. Sprinkle 2/3 of the crumb mixture into the prepared baking dish as evenly as possible. Using a flat-bottomed measuring cup or your hands, press the mixture into an even layer. Bake the crust in the preheated oven on the lowest rack until it’s lightly golden on the edges with a matte appearance in the middle, about 12 minutes. Remove and set aside until ready to use.

Make the Strawberry Filling:

1. Meanwhile, in a medium pot, stir together the granulated sugar, tapioca starch, and salt. Add the chopped strawberries and almond extract and cook over medium heat, stirring frequently, until the mixture is bubbling throughout, about 5 minutes. Remove from the heat and let cool for at least 10 minutes.
2. Transfer the strawberry filling onto the par-baked crust and spread into an even layer. Sprinkle the remaining crumb mixture evenly on the top.
3. Bake on the middle rack until the filling is slightly puffed up and the crumb mixture is a light golden color, 30 to 35 minutes.
4. Transfer to a wire rack and let cool completely. 
5. Make the glaze (optional): In a small bowl, whisk together the powdered sugar and heavy cream until smooth. Drizzle over the top of the bars. Cut into 16 pieces and serve.