Classic Canadian Butter Tarts with Flaky Pastry and Gooey, Caramelized Filling

• ### For the Crust
• 1 2/3 cups all-purpose flour (225g)
• 1 tbsp sugar
• 1 tsp kosher salt
• 2 sticks cold unsalted butter, cubed into 1/2 inch cubes
• 1 egg yolk
• 1 tsp vinegar
• Ice water to fill up to 1/2 cup
• ### For the Filling
• 2/3 cup packed brown sugar
• 1/4 cup maple syrup, corn syrup or golden syrup (I suggest half maple syrup and half golden syrup)
• 1/4 cup unsalted butter, softened
• 1 large egg
• 1/4 cup dried currants or pecans
• 1 tsp vanilla extract
• 1/2 tsp fine salt
• 1 tsp of lemon juice or vinegar, optional
• 1/2 tsp rum extract, optional

Instructions

1. 1

   In a 1/2 cup (120ml) measuring cup, add the egg yolk and vinegar, then top with ice water to measure 1/2 cup (120ml). Keep it in the fridge while you prepare everything else, as you want to ensure all the ingredients are chilled.

2. 2

   Combine the flour, sugar, salt, and butter in a stand mixer bowl.

3. 3

   Mix on low until large, fluffy crumbs form. Slowly add the water mixture.

4. 4

   Transfer the dough to a lightly floured work surface and fold it gently over itself 2–3 times to add more flakiness. Divide into two portions. While you are rolling half of your dough, keep the other half in the fridge. Roll the dough 4–5mm thick, which is slightly thicker than 1/8 inch (3mm). 1/4 inch (6mm) is just too thick, but 1/8 inch (3mm) will burn—so aim somewhere in between. Flour your work surface and rolling pin as needed to prevent sticking. Transfer to a large baking sheet, gently cover with plastic wrap, and refrigerate for at least an hour. Repeat with the remaining dough.

5. 5

   Using a 4-inch (10cm) round cookie cutter, cut out 12–16 dough circles. Reroll the scraps if necessary to maximize the dough. I find that each portion of the dough gives me 6 4-inch (10cm) circles, for a total of 12. When I reroll the scraps, I can get about 4 more circles. Gently press each circle into a standard muffin tin, ensuring the dough edges are flush with the top of the cups. Refrigerate for at least 2 hours, then prepare the filling near the end of the refrigeration.

6. 6

   Soak the currants in hot water, then drain.

7. 7

   Combine the sugar, salt, butter, vanilla, syrup (maple syrup, corn syrup, or golden syrup), and egg by gently mixing with a whisk by hand.

8. 8

   If desired, add 1 teaspoon (5ml) of lemon juice or vinegar for a subtle tang that balances the sweetness. Also add 1/2 tsp (2.5ml) of rum extract, if desired, for more complexity.

9. 9

   Divide the currants and filling into the chilled tart shells. Do not fill each tart more than halfway as it will overflow!

10. 10

    Bake at 425°F (220°C) for 14 minutes, then reduce the oven to 400°F (200°C) and bake for another 3–4 minutes until the tarts are golden brown, bubbling, and set.

11. 11

    Let cool completely before removing from the tin.