Prepare the Cream Filling: In a medium saucepan, whisk together 1 cup of whole milk, 1/2 cup of granulated sugar, 1/4 cup of all-purpose flour, and 1/4 teaspoon of salt. Heat this mixture over medium heat, stirring constantly until it thickens and begins to bubble (about 5-7 minutes). Remove from heat.

Add Egg Yolks: In a small bowl, whisk the 2 large egg yolks. Gradually add a scoop of the hot cream mixture to the yolks, whisking constantly to temper them. Then, add the yolk mixture back into the saucepan and cook for an additional 2 minutes, stirring continuously.

Flavor the Cream: Remove the saucepan from heat. Stir in 2 teaspoons of vanilla extract and allow the filling to cool to room temperature. Once cool, fold in 1 cup of whipped heavy cream until fully incorporated. Cover and refrigerate until ready to use.

Prepare the Croissant Dough: If using homemade croissant dough, roll it out into a rectangle approximately 1/4 inch thick. If using store-bought dough, follow the package instructions.

Shape the Pastries: Cut the dough into squares (approximately 3-4 inches per side). Take each square and form them into triangles by cutting diagonally. Seal the edges by pinching them together to prevent the filling from leaking.

Fry the Pastries: In a deep pot, heat oil over medium heat. Once hot, carefully add the pastries in batches, ensuring not to overcrowd the pot. Fry each side until golden brown (about 2-3 minutes per side). Use a slotted spoon to transfer them to a paper towel-lined plate to absorb excess oil.

Dust with Sugar: While still warm, generously dust the pastries with granulated sugar.

Fill the Pastries: Once cool, use a piping bag to fill the pastries with the cream filling through a small hole you can make at one corner. Ensure each pastry is adequately filled for maximum flavor.