In a large mixing bowl, combine all-purpose flour, sugar, and salt, whisking together until well mixed.

Cut cold unsalted butter into the flour mixture until it resembles coarse crumbs. Gradually add ice-cold water and mix until a cohesive dough forms.

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

Roll the chilled dough out to approximately 1/8-inch thickness on a floured surface.

Cut out shapes from the rolled-out dough, place 1-2 teaspoons of strawberry jam in the center, moisten edges with cold water, and seal.

Preheat oven to 375°F (190°C), line a baking sheet with parchment, arrange pies on sheet, brush with egg wash, and bake for 20-25 minutes.

Let the pies cool on a wire rack for about 10-15 minutes, then serve warm or at room temperature.