Place 2 ½ cups chopped strawberries, ½ cup granulated sugar, 1 Tbsp lemon juice, 2 tsp lemon zest, and 2 Tbsp lemon juice or water in a saucepan and heat over medium-high heat, uncovered.

Stir the mixture until it begins to boil. Lower the heat to medium-low, and let the filling simmer for about 10 minutes.

In a separate small bowl, make a slurry by combining the remaining 1 Tbsp + 1 tsp of water with 1 Tbsp + 1 tsp of cornstarch. Stir until completely smooth (no lumps). Add this cornstarch mixture to the strawberry filling and stir until it is incorporated.

Turn the heat up to medium-high, and be sure to stir constantly during this stage to prevent the filling from burning. It will go from cloudy/milky to clear and glossy as it thickens.

Cook until the mixture begins to boil, then reduce the heat to medium-low. Cook 1–3 minutes after it starts bubbling, until it’s thick enough to coat a spatula.

Turn off the heat and pour the filling into a wide and shallow dish to speed up the cooling process. Place the filling in the refrigerator to cool while you work on the crust.

Preheat the oven to 350 F / 175 C and line the inside of an 8x8-inch baking dish with parchment paper.

Whisk together 1 ¾ cups (230g) all-purpose flour, ⅓ cup (66g) granulated sugar, ⅓ cup (66g) of packed brown sugar, ¾ tsp baking powder, and ½ tsp fine salt in a large bowl.

Then stir ¾ cup (170g) of melted and cooled butter into the dry ingredients with a rubber spatula. Keep mixing until there are no remaining patches of dry ingredients, and the crumble looks moist but crumbly.

Press about ⅔ of the mixture (360g) into the bottom of the prepared pan in an even layer. Gently spread the strawberry filling over the crust. Then sprinkle the remaining crumble over the top of the filling.

Bake for 35 to 40 minutes or until the edges are just beginning to brown.

Let the bars cool at room temperature for about 20 minutes, then place the pan on a pot holder and move it to the fridge to cool for about an hour.

Once chilled, lift the bars out of the pan and slice into 16, 2-inch squares.

In a small bowl, whisk together ½ cup (65g) of powdered sugar, 1 Tbsp (15g) milk of your choice, 1 tsp (5g) vanilla extract, and a pinch of fine salt. Drizzle the glaze over the fully cooled bars, then enjoy!