Prepare oven and pan: Preheat the oven to 350°F (175°C). Line a standard loaf pan with parchment paper and set aside.
Cream butter and sugar: In the bowl of a stand mixer fitted with the paddle attachment (or a hand mixer), beat the butter and sugar together until light and well combined.
Add eggs: Add the eggs and vanilla extract and mix until smooth. Add the sourdough starter and mix again until fully incorporated.
Add dry ingredients: Add the flour, salt, and baking powder to the bowl and mix just until the batter is smooth and no dry spots remain. Do not overmix.
Prepare strawberries: In a small bowl, toss the diced strawberries with 2 tablespoons of flour. Gently fold the strawberries into the batter.
Pour batter: Pour the batter into the prepared loaf pan and smooth the top with the back of a spoon.
Bake the bread: Bake for 60–70 minutes, or until a toothpick inserted into the center comes out clean or with just a few moist crumbs.
Cool: Remove the bread from the oven and allow it to cool in the pan for 10–15 minutes, then transfer to a wire rack to cool completely.
Prepare the glaze: Once the bread is fully cooled, whisk together the powdered sugar, melted butter, finely diced strawberries, vanilla extract, and milk or cream until smooth.
Glaze the bread: Spoon or pour the glaze over the cooled loaf. Allow the glaze to set before slicing and serving.