01 -
Let it cool off for at least 10 minutes. Scoop it up warm with some ice cream if you've got it.
02 -
Slide the pan into your oven. Let it bake around 35–40 minutes. You want the top to go golden and the sides to start bubbling.
03 -
Grab a new bowl for the topping. Mix in your flour, oats, brown sugar, and cold butter. Use your fingers, a fork, or a pastry cutter until it gets crumbly. Sprinkle that all over your rhubarb without squishing it down.
04 -
Toss the rhubarb chunks with the sugar and cornstarch—just use less starch for fresh rhubarb. Spread this right in your greased pan.
05 -
Heat your oven to 190°C. Grease up a 20 x 20 cm or 23 x 23 cm pan lightly.