Rhubarb Crumble - cooking recipe

Ingredients

2 lbs rhubarb, chopped into 1/2 in pieces
1/4 cup sugar (superfine)
1 tablespoon butter
1 tablespoon vanilla extract
1 tablespoon cornstarch
For the Crumble Topping
1 cup all-purpose flour
1 teaspoon baking powder
1/2 cup unsalted butter, cold and diced
3 tablespoons vanilla sugar (can substitute ordinary sugar)
3 tablespoons brown sugar

Preparation

Place a baking sheet in the oven and preheat the oven to 375\u00b0F
Heat the rhubarb in a pan on medium to medium low with the 1/4 sugar, 1 T butter, vanilla, and cornstarch for about 5 minutes, until the rhubarb is glossy and everything has melted together. Transfer to an 8 1/2 in pie plate (approx. 1 1/2 in deep).
To make the crumble topping, place the flour and baking powder in a bowl and rub in the butter until it is thoroughly combined, with a texture like soft crumbs.
Using a fork, stir in the sugars. Spread evenly over the fruit, attempting to cover all of it. (Exposed parts will bubble up). Bake on the sheet for 35-45 minutes. It's okay if it bubbles over a bit, this is what the pan is for.).