01 -
Beat the butter, white sugar, and brown sugar on medium speed with a paddle attachment until smooth and fluffy, about 3 minutes. Scrape sides, then add in the egg and vanilla and keep mixing. In another bowl, whisk the flour, baking powder, and salt together. Gradually add the dry mix to the butter mixture and stir until just blended. Cover and set aside 2 cups of the dough for topping. Spread the rest of it firmly into a parchment-lined 8x8 pan.
02 -
Preheat to 350°F (175°C). Bake the crumb layer for 13 to 15 minutes, just until the center is thickened and the edges get golden brown. Let it cool a bit before adding the next layer.
03 -
Rinse, hull, and quarter fresh berries (skip this if frozen ones are used). Toss the strawberries, sugar, cornstarch, and water (only if fresh) into a medium pot over medium-low heat. Stir regularly while gently mashing the berries to release their juices. Cook for 6–8 minutes until it thickens. Cool it down a little.
04 -
Spread your cooked strawberry mixture evenly over the base. Use the saved dough to create small flattish pieces and scatter them on top, leaving parts of the strawberry layer visible.
05 -
Put everything in the oven again at 350°F (175°C) for 40–45 minutes. You’ll know it’s ready when the topping is golden and the strawberry mix bubbles around the edges. Cool completely on a rack.
06 -
In a little bowl, whisk sifted powdered sugar, milk (or cream), and vanilla if you’re using it. If too thick, add a splash more milk; if too thin, more sugar. Drizzle over the cooled bars.