1 cup buttermilk
3/4 cup sugar
1/4 cup canola oil
1 tsp vanilla extract
2 cups flour
2 tsp baking powder
2 cups frozen raspberries (unthawed)
Preheat oven to 400F. Line the cups of a 12-cup muffin tin with paper liners.
In a large mixing bowl, stir together the buttermilk, sugar, oil, egg and vanilla until smooth. Zest and juice the lemon into the buttermilk mixture; stir again until combined.
In a separate bowl, stir together the flour, baking powder and salt. Add to the wet ingredients and fold until almost combined. Gently fold in the still-frozen raspberries, being careful not to break them up. Spoon batter into prepared muffin cups.
Bake in preheated oven for 20-25 minutes, or until a toothpick inserted into the centre of each muffin comes out clean. Let cool in pan for 5-10 minutes, then turn out onto a wire rack to cool completely.