Preheat oven to 400°F (200°C). Fit 12 muffin tin with liners and spray with cooking spray.
Combine ½ cup flour, ½ tsp cinnamon, and ½ cup brown sugar in medium bowl for topping.
Add 3 tbsp melted butter to topping mixture and mix until crumbly.
In saucepan, melt ½ cup butter on medium heat, whisking constantly until foam settles and butter turns golden brown (5-8 minutes). Remove from heat immediately.
Whisk in 1 cup sugar, 2 eggs, ½ cup milk, 1 tbsp vanilla extract, and ½ tbsp almond extract (if using) until smooth.
In separate bowl, sift 2 cups flour, 2 tsp baking powder, and ½ tsp salt. Add to browned butter mixture in 2 batches, folding gently until just combined. Avoid overmixing.
Fold in 2 cups blueberries (berries should be evenly coated with dry ingredients in bowl first for better suspension).
Divide batter evenly among prepared muffin cups, filling ⅔ full. Sprinkle topping generously on each muffin.
Bake 25 minutes or until golden and toothpick inserted in center comes out clean. Let cool for 10 minutes before serving.