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Costco Muffin Recipe

Costco Blueberry Muffins Recipe

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Prep Time 15 minutes
Cook Time 28 minutes
Total Time 43 minutes
Servings: 6 servings
Calories: 480
Ingredients Method Notes

Ingredients
  

  • 2 1/2 cups all-purpose flour
  • 1 1/4 cups granulated sugar
  • 2 tsp baking powder
  • 1/2 tsp baking soda
  • 1/2 tsp fine salt
  • 1 cup buttermilk
  • 1/2 cup vegetable oil
  • 2 large eggs
  • 1 tsp vanilla extract
  • 2 cups fresh or frozen blueberries
  • 1 tbsp all-purpose flour (for tossing blueberries)
  • 1/4 cup all-purpose flour (for streusel)
  • 1/4 cup packed light brown sugar
  • 2 tbsp unsalted butter, melted
  • Pinch of ground cinnamon

Method
 

  1. Preheat oven to 375°F, line a jumbo 6-cup muffin pan, and whisk together the 2 1/2 cups flour, sugar, baking powder, baking soda, and salt in a large bowl.
  2. In a medium bowl, whisk buttermilk, oil, eggs, and vanilla until smooth.
  3. Fold wet ingredients into dry until just combined, then toss blueberries with 1 tbsp flour and gently fold them in. Divide batter among the jumbo cups and sprinkle with streusel made from 1/4 cup flour, brown sugar, melted butter, and cinnamon.
  4. Bake at 400°F for 5 minutes, then reduce to 375°F and bake 20 to 25 minutes until golden and a toothpick comes out clean.
  5. Cool in the pan 5 minutes, then transfer to a rack. Serve warm or at room temperature.

Notes

If you don’t have buttermilk, stir 1 tbsp lemon juice into 1 cup milk and rest 5 minutes. The batter is thick on purpose, so don’t thin it. For the tallest muffins, stick with the high-heat start. Frozen blueberries work straight from the freezer, no thawing needed.