Raspberry Maple Walnut Muffins with Toasted Oats

Steps

1. Heat the oven to 400°F (200°C) and line a 12-cup muffin pan with paper liners.
2. Spread the walnuts on a small sheet pan and toast for 5 to 6 minutes until fragrant, then cool. Melt the butter and let it cool while you toast.
3. Make the topping: in a small bowl mix the oats, 20 g (one quarter) of the brown sugar and 30 g (one third) of the toasted walnuts; set aside.
4. In a large bowl whisk the flour, baking powder, baking soda, salt and cinnamon.
5. In another bowl whisk the eggs, the remaining 60 g of brown sugar, the maple syrup, sour cream, milk and vanilla, then whisk in the melted butter.
6. Pour the wet mixture into the flour mixture and fold with a spatula until a few streaks of flour remain.
7. Gently fold in the raspberries and the remaining 60 g (two thirds) of walnuts just until no dry flour shows; do not overmix.
8. Divide the batter among the cups and sprinkle the oat-walnut topping evenly over each muffin.
9. Bake 5 minutes at 400°F (200°C), then lower to 375°F (190°C) and bake 13 to 15 minutes more, until golden and a toothpick in the center comes out clean.
10. Cool in the pan 5 minutes, then move to a rack and cool at least 15 minutes before serving.