Ingredients:

  • ½ cup All-Purpose Flour (for streusel)
  • ¼ cup packed Light Brown Sugar (for streusel)
  • 2 Tbsp Granulated Sugar (for streusel)
  • 1 tsp Ground Cinnamon (for streusel)
  • ¼ cup (½ stick) very cold Unsalted Butter, diced (for streusel)
  • 1 ¾ cups All-Purpose Flour, sifted (for loaf)
  • ¾ cup Granulated Sugar (for loaf)
  • 2 tsp Baking Powder
  • ½ tsp Fine Sea Salt
  • ½ cup (1 stick) room temperature Unsalted Butter, softened (for loaf)
  • 2 Large Eggs, room temperature
  • 1 tsp Vanilla Extract
  • ½ cup room temperature Buttermilk (or whole milk mixed with 1 tsp lemon juice)
  • 1 cup Fresh or Frozen Blueberries
  • 1 Tbsp Additional Flour (for coating berries)
  • 1 cup sifted Powdered Sugar (for glaze)
  • 2 Tbsp Fresh Lemon Juice (for glaze)
  • 1 Tbsp Milk or Water (for glaze)

Instructions:

  1. Combine Streusel Dry Ingredients: Whisk together the ½ cup flour, both sugars, and cinnamon in a medium bowl.
  2. Cut in the Butter: Add the cold, diced butter. Using your fingers or a pastry cutter, quickly work the butter into the dry mixture until crumbly, forming pea-sized clumps. Place the streusel mixture in the refrigerator.
  3. Preheat and Prepare: Preheat the oven to 350°F (175°C). Grease and line the 9x5 inch loaf pan with parchment paper, allowing the paper to overhang the sides.
  4. Whisk Dry Ingredients (Loaf): In a large bowl, whisk together the 1 ¾ cups flour, baking powder, salt, and granulated sugar until thoroughly combined.
  5. Add Butter: Add the room temperature butter to the dry ingredients. Beat on medium speed for 2-3 minutes until the mixture is light, fluffy, and resembles wet sand (the reverse creaming method).
  6. Combine Wet Ingredients: In a separate small bowl, lightly whisk the eggs, vanilla extract, and buttermilk until just combined.
  7. Incorporate Wet: Pour the wet mixture into the dry-butter mixture. Beat on low speed until just combined—do not overmix.
  8. Prepare Blueberries: If using frozen blueberries, toss them gently in the additional 1 tablespoon of flour to prevent sinking. Gently fold the blueberries into the batter using a rubber spatula.
  9. Assembly: Scrape the batter into the prepared loaf pan and spread evenly. Retrieve the chilled streusel topping and evenly distribute it over the batter. Gently pat the topping down slightly.
  10. Bake: Place the loaf pan in the preheated oven. Bake for 55–60 minutes. If the top browns too quickly, loosely tent with aluminum foil.
  11. Test and Cool: Insert a long toothpick or skewer into the center; it should come out clean. Remove the loaf and let it cool in the pan for 15 minutes before using the parchment sling to lift it out and transfer it to a wire rack. Cool completely before glazing.
  12. Glaze (Optional): Whisk together the sifted powdered sugar, lemon juice, and milk/water until smooth and pourable. Drizzle the glaze generously over the completely cool loaf and let the glaze set for 10-15 minutes before slicing.