Set your oven to 390°F (200°C). If your muffin pan could talk, it would thank you for greasing it or lining it with paper cups. Want sky-high muffins? Line every other cup in your 12-cup pan—this gives them room to rise and prevents spreading.
In a mixing bowl, pour in the milk, vinegar (or lemon juice), oil, vanilla extract, and light brown sugar. Whisk with enthusiasm until the sugar dissolves completely—no grainy bits allowed!
Add the flour, baking powder, baking soda, cinnamon, and salt. Stir gently but with purpose. Gradually mix the dry ingredients into the wet, using a hand whisk to bring everything together into a smooth, luscious batter.
Now, fold in the grated carrots and walnuts (if you're feeling nutty). Stir just enough to combine—no overmixing, or your muffins will protest by turning dense.
Spoon the batter into the muffin cups all the way to the top. Yes, all the way! This ensures beautifully domed muffins worthy of a bakery window. Sprinkle some coarse sugar on each muffin.
Slide the pan into the oven and bake at 390°F (200°C) for 8 minutes. Then, without opening the oven, lower the temperature to 350°F (175°C) and bake for another 7- 8 minutes. When a toothpick inserted in the center comes out clean, your muffins are ready to shine.
Let them cool completely before serving. For a classic carrot cake flavor top them with cream cheese icing for that extra wow factor.