Coffee Cream Cheese Cake: A Deliciously Decadent Dessert

1. Mix the Dry Ingredients:
   • In a medium-sized bowl, sift together the flour, baking powder, and instant coffee. This will ensure there are no lumps and the coffee is evenly distributed throughout the dough.
2. Cream the Butter and Sugar:
   • In a separate large bowl, cream together the softened butter and sugar until the mixture becomes light and fluffy. This can be done using an electric mixer or a whisk. Once creamed, add the egg yolk and vanilla sugar, and continue to mix until smooth.
3. Combine the Ingredients:
   • Gradually add the dry ingredients into the butter mixture, stirring until the dough starts to come together. If the dough feels too dry or crumbly, add 2 tablespoons of water, one tablespoon at a time, until the dough is soft and pliable but not sticky.
4. Chill the Dough:
   • Wrap the dough in plastic wrap and chill it in the refrigerator for at least 30 minutes. Chilling helps the dough hold its shape while baking and makes it easier to handle.

Step 2: Prepare the Coffee Custard Filling

5. Heat the Milk and Sugar:
   • In a medium saucepan, heat the milk and sugar over medium heat, stirring occasionally, until the sugar has dissolved and the milk is hot but not boiling.
6. Make the Cornstarch Mixture:
   • In a small bowl, mix the cornstarch and instant coffee with a little cold milk (about 2 tablespoons) to create a smooth paste.
7. Thicken the Custard:
   • Once the milk is hot, slowly pour the cornstarch mixture into the pan, whisking constantly. Continue to cook the custard over low heat, whisking until it thickens to a pudding-like consistency. This will take about 3-5 minutes.
8. Finish the Custard:
   • Remove the custard from the heat and whisk in the egg yolk, butter, and vanilla sugar. Whisk until the mixture is smooth and the butter is completely melted. Let the custard cool slightly before using it as a filling.

Step 3: Assemble the Cake

9. Roll Out the Pastry:
   • Preheat your oven to 180°C (350°F). Once the dough has chilled, roll it out on a lightly floured surface to fit your tart or pie pan. Press the dough into the pan and trim any excess. You can use the leftover dough to create decorative edges or cut into strips for a lattice top.
10. Blind Bake the Pastry:
    • Line the pastry with parchment paper and fill it with pie weights or dried beans. Bake for 10-12 minutes, or until the edges are lightly golden. After this time, remove the parchment paper and weights, and bake for an additional 5 minutes to crisp up the bottom.
11. Fill the Pastry:
    • Once the pastry shell is baked and cooled, pour the coffee custard filling into the shell, smoothing it out evenly.