Filling

• ¾ cup packed brown sugar
• ½ cup Maple Syrup 
• ⅓ cup butter, melted
• 2 eggs
• 1 tbsp cider vinegar
• ½ tsp salt
• ½ cup chopped walnut halves
• ¼ cup dried currants
• ¼ cup golden raisins 

Sour Cream Pastry: 

• 1-¼ cups all-purpose flour
• ¼ tsp salt
• ¼ cup cold butter, cubed
• ¼ cup cold lard, cubed
• 2 tbsp ice water (approx)
• 4 tsp sour cream (or cheat and just use store-bought pastry like we do...) 

Sour Cream Pastry 

In bowl, whisk flour with salt. Using pastry blender, cut in butter and lard until in fine crumbs with a few larger pieces.

Whisk water with sour cream; drizzle over flour mixture, tossing briskly with fork and adding more water if necessary to form ragged dough. Press into disc; wrap and refrigerate until chilled, about 30 minutes. (Make-ahead: Refrigerate for up to 3 days.)

On lightly floured surface, roll out pastry to generous ⅛-inch (3 mm) thickness. Using 4-inch (10 cm) round cutter, cut out 12 circles, rerolling and cutting scraps.  Fit into 12 muffin cups; refrigerate for 30 minutes.

Meanwhile, whisk together brown sugar, maple syrup, butter, eggs, vinegar and salt. Divide walnuts, currants and raisins among pastry shells. Spoon scant ¼ cup filling into each shell.

Bake in 180°C; (350°F) oven until filling is set and pastry is golden, 20 to 25 minutes. Run thin knife around edges to release tarts. Let cool in pan on rack for 20 minutes.

Transfer to rack; let cool completely. (Make-ahead: Store in single layer in airtight container at room temperature for up to 24 hours.)