Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking pan.

In a mixing bowl, whisk together 1.5 cups of all-purpose flour and ½ cup of powdered sugar. Cut in ¾ cup of cold, cubed butter until the mixture resembles coarse crumbs.

Press the crust mixture firmly into the bottom of the greased baking pan. Bake for 15 minutes or until edges turn light golden brown.

Mix 2 cups of chopped rhubarb with 1 cup of granulated sugar. In another bowl, lightly beat 2 eggs and combine with ¼ cup of flour and ½ teaspoon of vanilla extract.

Pour the rhubarb mixture evenly over the pre-baked crust.

Bake for 30-35 minutes or until the filling is set and the top is light golden color.

Let the bars cool completely in the pan. Refrigerate for at least one hour before cutting into squares.