BEST Canadian Butter Tarts

Name: BEST Canadian Butter Tarts
Prep time: 30 min
Cook time: 15 min
Total time: 45 min
Cuisine: Canadian
Ingredients: 3 cups (375g) all-purpose flour (plus more for dusting); 1/2 tsp baking powder; 1/2 tsp salt; 1/2 cup (114g) lard (room temperature); 1/2 cup (114g) unsalted butter (room temperature); 1 large egg; 1 tsp white vinegar; about 1 cup (250ml) cold water; 3/4 cup (165g) packed brown sugar; 1/3 cup (75g) unsalted butter; 1 Tbsp table or whipping cream; 1 tsp vanilla extract; 1/2 cup chopped pecans, walnuts, raisins or chocolate chips