Ingredients:
- 1/2 cup All-Purpose Flour (for streusel)
- 1/4 cup Granulated Sugar (for streusel)
- 1 tsp Ground Cinnamon (for streusel)
- 3 Tbsp Unsalted Butter, cubed and very cold (for streusel)
- 2 cups All-Purpose Flour
- 3/4 cup Granulated Sugar
- 1 Tbsp Baking Powder
- 1/2 tsp Baking Soda
- 1 tsp Ground Cinnamon
- 1/2 tsp Fine Sea Salt
- 2 Large Eggs, room temperature
- 1 cup Buttermilk, full fat
- 1/4 cup Vegetable Oil (neutral)
- 1/4 cup Unsalted Butter, melted and cooled
- 1 tsp Vanilla Extract
Instructions:
- Preheat oven to 425°F (220°C). Line the muffin tin with paper cases or grease thoroughly.
- Make the Streusel: In a small bowl, combine 1/2 cup flour, 1/4 cup sugar, and 1 tsp cinnamon. Cut in the very cold, cubed butter using your fingertips or a fork until the mixture resembles coarse, pea-sized crumbs. Set aside in the fridge.
- Combine Dry Ingredients: In the largest mixing bowl, whisk together 2 cups flour, 3/4 cup sugar, baking powder, baking soda, 1 tsp cinnamon, and salt until well combined.
- Combine Wet Ingredients: In a separate medium bowl, lightly whisk the eggs. Add the buttermilk, oil, melted butter, and vanilla extract. Whisk briefly until just combined.
- Mix Batter (Crucial Step): Pour the wet ingredients into the dry ingredients. Using a rubber spatula, gently fold the mixture together until just combined. Stop mixing when there are still a few streaks of flour visible (the batter should look lumpy and thick).
- Fill Tins: Using an ice cream scoop, divide the batter evenly among the 12 prepared muffin cups, filling them about 3/4 full or slightly more.
- Top the Muffins: Retrieve the streusel from the fridge and crumble a generous spoonful over the top of each muffin. Press lightly so it adheres slightly.
- Bake (The High-Heat Trick): Place the tin in the preheated oven. Bake at 425°F (220°C) for exactly 5 minutes.
- Reduce Heat and Finish: Without opening the oven door, reduce the oven temperature to 375°F (190°C) and continue baking for another 15–17 minutes, or until the muffins are golden brown and a skewer inserted comes out clean.
- Cool: Let the muffins cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.