Preheat oven to 400 degrees F and prepare 12 muffin cups with paper liners.
In a large bowl, combine the flour, brown sugar, baking powder, cinnamon, baking soda, and salt. In another large bowl, combine the coffee, oil, and egg. Stir the dry ingredients into the coffee mixture until just combined and moist. You don't want to over-mix!
Fill the paper-lined muffin cups with enough muffin batter to cover the bottom. Drop 1 teaspoon of raspberry preserves into the center of each muffin cup and top with remaining batter.
For the Topping:
In a small bowl, combine the flour, brown sugar, and cinnamon. Cut in butter until mixture resembles coarse crumbs (works best using a pasty blender), and stir in walnuts.
Sprinkle topping evenly over the muffin batter and bake for 18-20 minutes. Remove pan from oven and cool 5 minutes.
For the Vanilla Glaze:
In a small bowl, combine powdered sugar, milk, and vanilla. Mix to a smooth, thick consistency. Add more milk to thin, if necessary. Drizzle glaze over warm muffins and serve.
- Not a coffee drinker? Substitute 3/4 cup of milk for the coffee in the muffin batter. - Change up the flavors by trying a different fruit preserve for the filling. Orange marmalade is another one of my favorites!