Preheat oven to 350°F (175°C). Line 10 muffin cups with paper liners.

In a large bowl, whisk together 1 3/4 cups all-purpose flour, 1 1/2 teaspoons baking powder, 1/2 teaspoon salt, and 1/2 teaspoon ground nutmeg.

In a medium bowl, whisk together 3/4 cup of sugar, 1 egg, and 1/3 cup vegetable oil until well blended.

Whisk in 3/4 cup milk until blended.

Add the egg mixture to the flour mixture and stir until just blended.

Divide batter equally among prepared muffin cups.

Drop a heaping teaspoon of seedless raspberry preserves on top of each muffin.

Bake for 20-25 minutes, or until tops are golden and a pick inserted into the center comes out clean.

Let cool in pan on a wire rack for 3 minutes, then transfer to the rack to cool while you prepare the topping.

In a small bowl, combine the remaining 1/4 cup sugar with 1 teaspoon ground cinnamon.

Generously brush warm muffin tops with 1/4 cup melted unsalted butter, then sprinkle with cinnamon mixture.

Let cool completely before serving.