1/2 cup (1 stick) unsalted butter, room temperature
2/3 cup sugar
2/3 cup orange marmalade
1 cup almonds
1 cup all-purpose flour
1 teaspoon baking powder
1/4 teaspoon baking soda
3/4 teaspoon salt
3 large eggs, room temperature
3/4 cup buttermilk
1 teaspoon vanilla extract
1 cup cold heavy cream, whipped to medium peaks with 3 tablespoons sugar
Preheat oven to 350 degree, with rack in upper-third position. Line 18 muffin-pan cups with paper liners.
In a large bowl, using an electric mixer, beat butter, sugar and 1/3 cup marmalade until pale yellow and fluffy, 4 minutes. Meanwhile, in a food processor, process almonds until finely ground. Add flour, baking powder, baking soda, and salt and process until almonds are completely incorporated into flour mixture.
With mixer on low, beat eggs, one at a time, into butter mixture, scraping down bowl after each addition. Add buttermilk and flour mixture each in 3 additions (ending with flour), scraping down bowl after each addition. Beat in vanilla.
Fill each muffin cup with 1/4 cup batter. Bake until golden brown and a toothpick inserted in center of cupcake comes out clean, 22 to 24 minutes, rotating pans halfway through. Let cupcakes cool in pans on wire racks.
Top each cupcake with a dollop of whipped cream and a teaspoon of marmalade.