01 - Whisk together the sourdough starter, lukewarm milk, eggs, melted butter, and vanilla extract in a large mixing bowl until completely smooth and well incorporated.
02 - Sift together the flour, sugar, salt, baking powder, and baking soda in a separate medium bowl to ensure even distribution of leavening agents.
03 - Pour the dry ingredients into the wet mixture and fold gently using a rubber spatula until just combined. Stop mixing as soon as flour streaks disappear to prevent tough texture.
04 - Gently fold in the diced strawberries and white chocolate chips, taking care not to crush the fruit or overwork the batter.
05 - Cover the bowl with plastic wrap or a clean kitchen towel. Let rest at room temperature for 3 to 4 hours, or refrigerate overnight for enhanced flavor development through fermentation.
06 - Preheat the oven to 350°F. Generously grease a 9x5-inch loaf pan with butter and line with parchment paper, leaving overhang for easy removal.
07 - Stir the rested batter gently to redistribute ingredients. Scrape into the prepared loaf pan and smooth the top with an offset spatula.
08 - Bake for 50 to 60 minutes until a wooden skewer inserted into the center emerges clean and the top is deep golden brown. If browning too quickly, tent with foil after 40 minutes.
09 - Let the loaf cool in the pan for 15 minutes before lifting out using parchment overhang. Transfer to a wire rack to cool completely before slicing for clean cuts.