• Preheat the oven to 350º. Line an 8 x 8 inch baking pan with parchment paper and butter the sides.

Filling

• Add ½ cup of sugar, rhubarb, 1 teaspoon of vanilla and ¼ cup water to a saucepan.
• Cook over medium heat until the rhubarb has softened, about 10 minutes. This can vary depending on the rhubarb.
• Let it cool completely. Once cooled drain with a metal sieve to remove excess liquid.

Crumble

• Add ½ cup of flour and ¼ cup of sugar to a small bowl.
• Add the butter to a small saucepan over medium heat and cook until it begins to turn brown.
• Pour the butter over the flour and sugar mixture and stir with a fork until incorporated. Set aside.

Cake

• Cream butter and sugar in a large mixing bowl of an electric mixer until light and fluffy, about 2 minutes. Add the egg and mix until incorporated. Add yogurt and vanilla and mix well.
• Slowly add the flour and mix just until there is no flour visible.
• Spread half of the batter in the prepared pan, it will barely cover the bottom.
• Place half of the drained rhubarb on the cake batter.
• Place the rest of the cake batter over the rhubarb, it does not have to completely cover the rhubarb. Top with the remaining rhubarb.
• Sprinkle all of the crumble over the cake and bake for 40-45 minutes until the crumble is golden brown and a toothpick comes out with just a few crumbs.