– 4 cups rhubarb cut into bite sized pieces – 1 cup granulated sugar – 1 teaspoon vanilla extract – 2 tbsp lemon juice or water – 2 tbsp cornstarch
– 2/3 cup all-purpose flour – 2/3 cup rolled oats – 2/3 cup light brown sugar packed – ½ teaspoon ground cinnamon – Pinch of salt – 1/2 cup unsalted butter cold