Step 1

Preheat oven to 350 degrees. Make the dough: Process pecans in a food processor until finely ground (you should have about 1/2 cup); set aside. Put mascarpone or cream cheese and butter into the bowl of an electric mixer fitted with the paddle attachment. Mix on medium-high speed until well blended. Add flour, ground pecans, and salt; mix just until dough comes together. Alternatively, stir together ingredients with a wooden spoon in a large bowl.

Step 2

Roll dough into eighteen 1-inch balls, and press into bottoms and up sides of cups of mini-muffin tins.

Step 3

Make the filling: Whisk the egg, sugar, maple syrup, vanilla, butter, and salt in a small bowl. Stir in pecans. Spoon about 1 1/2 teaspoons filling into each muffin cup.

Step 4

Bake pecan tassies until crust begins to turn golden, about 20-22 minutes. Let cool completely in tins on wire rack. Unmold. Pecan tassies can be stored in single layers in airtight containers up to 3 days.