Preheat the oven to 350°F (175°C). Gather ingredients and equipment.

Combine 1 cup of flour, 2 tablespoons of powdered sugar, and a pinch of salt. Blend in 1/2 cup softened butter until it resembles coarse crumbs. Press into the bottom of a 9x13-inch baking pan and bake for 10 minutes.

Whisk together 2 beaten eggs, 1 1/4 cups granulated sugar, and 1/4 cup flour until smooth. Gradually stir in 1 cup sour cream.

Layer 2 cups chopped strawberries and 3 cups diced rhubarb over the crust.

Pour the custard mixture over the fruit, covering evenly. Bake for 40-45 minutes until edges are lightly golden.

Allow to cool at room temperature for 30 minutes, then chill in the refrigerator for 1-2 hours.

Slice and serve, optionally topped with whipped cream.