In a large mixing bowl, combine the flour, sugar, salt, and baking powder. Stir until evenly blended.

Pour the vegetable oil into the dry ingredients and mix until it starts to clump together.

Gradually add the cold water, stirring until the dough comes together. It’s okay if a few small crumbles remain; avoid overmixing.

Shape the dough into a disc, wrap it tightly in plastic wrap, and refrigerate for at least 30 minutes.

Peel the apples and dice them finely. The smaller the pieces, the better.

Toss the diced apples in a small bowl with the sugar and cinnamon, making sure they're evenly coated.

Line your baking sheets with parchment paper.

Roll out the chilled dough between two lightly floured pieces of parchment paper until it’s about ¼ inch thick.

Use a round cutter (around 3 inches in diameter) to cut out as many circles as possible. You can reroll the dough once if needed, but avoid working it too much.

Place half of the dough rounds on a prepared baking sheet. Spoon about 1 tablespoon of the apple mixture onto the center of each round.

Lightly brush the edges of the dough around the filling with a bit of oat milk or water.

Top each filled round with another dough circle, pressing down gently around the edges to remove air and seal them.

Brush the tops with oat milk and sprinkle raw cane sugar over each one. Cut a small vent on the top of each pastry using a sharp knife.

Chill the assembled pastries in the refrigerator for about 15 minutes before baking.

Preheat the oven to 375°F about 10 minutes before baking.

Bake the pastries for 24-27 minutes, or until the edges turn golden brown.

Remove from the oven and let them cool completely before serving.