Preheat & prep: Preheat oven to 350°F (175°C) and grease a 9x5-inch loaf pan.
Mix fruit & flour: Toss diced strawberries and rhubarb with 2 tbsp flour; set aside.
Combine dry ingredients: In a bowl, whisk 2 cups flour, baking powder, and salt.
Make batter: In a large bowl, whisk sugar, oil, milk, egg, and vanilla. Stir in dry ingredients.
Fold in fruit: Gently fold in the strawberry-rhubarb mixture.
Bake: Pour batter into the pan and bake for about 1 hour or until a toothpick comes out clean.
Cool: Let cool in the pan for 10 minutes, then transfer to a wire rack.
Glaze & serve: Whisk powdered sugar with milk, drizzle over the loaf, let set, then slice and enjoy!