Hokkaido Milk Bread

Name: Hokkaido Milk Bread
Ingredients: Tangzhong:; 6 tablespoons water; 2 tablespoons bread flour; Assembly:; 1/4 cup whole milk, plus 1 splash for the egg wash; 1 1/2 teaspoons active dry yeast; 2 1/2 cups (about 320 grams) bread flour, plus up to ¼ cup (30 grams) more; 1/4 cup sugar; 1 teaspoon kosher salt; 1/4 cup heavy whipping cream; 1 tablespoon sweetened condensed milk or milk powder (optional); 2 large eggs; 2 tablespoons unsalted butter, softened, divided