Blend 2 cups of all-purpose flour and ½ cup cold butter until it resembles coarse crumbs. Gradually add 4-6 tablespoons of ice-cold water and mix until it comes together. Form into a disc, wrap, and chill for at least 30 minutes.

In a saucepan over medium heat, whisk together 2 eggs, ½ cup sugar, and 1 cup milk until thickened, about 5-7 minutes. Remove from heat and chill fully.

Roll the chilled dough into a rectangle, about 1/4 inch thick. Cut into 4-6 squares.

Place a spoonful of custard and a dollop of raspberry jam on each square. Fold corners to center and pinch to seal.

Transfer to a parchment-lined baking sheet, cover, and let rise until doubled, about 30-45 minutes.

Preheat the oven to 375°F (190°C). Bake for 18-20 minutes until golden brown.

Cool on a wire rack for about 5-10 minutes. Sprinkle with powdered sugar if desired.