Preheat the oven to 350°F. Line an 8x8-inch baking pan with parchment paper.
In a small saucepan, melt the butter (or you can do this in the microwave, either works).
To make the crust and topping: In a medium bowl, add the flour, cocoa powder, cane sugar, light brown sugar, and vanilla extract, and mix together. Add in the melted butter and stir to combine completely.
Reserve ½ cup for the topping and set aside. Using your hands, or a measuring cup, press the remaining crust into the bottom of the pan evenly.
Bake the crust in the preheated oven for 15 minutes.
To make the filling: In a small bowl, add the strawberry jam and cornstarch and stir together until combined.
When the crust is done baking, remove from the oven. Add the strawberry filling on top. And sprinkle the remaining crumb topping on top.
Return to the oven and bake for another 27 to 30 minutes, or until the topping looks dry. Allow to cool in the pan completely.
To make the glaze: In a small bowl, add the powdered sugar and water and whisk until you have a smooth glaze.
Drizzle the glaze over the top of the bars.
Cut into 9 bars.
Store in a cool dry place for up to 3 days.