These classic chocolate chip muffins have a lovely crispy, sky-high muffin top once baked.
Preheat oven to 400°F (200°F). Line 12 muffin cups with paper liners. In large bowl, whisk together flour, sugar, baking powder, baking soda and salt. Stir in chocolate chips; set aside.
Whisk together buttermilk, melted butter, eggs and vanilla in separate bowl. Stir buttermilk mixture into flour mixture just until moistened. Divide batter evenly among prepared muffin cups.
To substitute milk for buttermilk, place 1 tbsp (15 mL) lemon juice or vinegar in measuring cup; add enough milk to measure 3⁄4 cup (175 mL). Let stand for 15 minutes before using.
Bake for 18 to 20 minutes or until muffins are golden brown and toothpick inserted in center of muffin comes out clean. Transfer pan to rack; let cool for 10 minutes. Serve warm or let cool completely.