Preheat oven to 375°F (190°C) and line two baking sheets with parchment paper; gather ingredients for a smooth workflow.

In a bowl or food processor, combine flour, sugar, and salt; add cold butter and pulse until coarse crumbs form, then drizzle ice water and pulse until dough starts to come together.

Form dough into a 1" thick disc, wrap in plastic, and refrigerate for at least 30 minutes to achieve maximum flakiness.

Beat softened cream cheese with sugar, lemon zest, lemon juice, and vanilla until smooth and creamy, being careful not to overbeat.

Roll chilled dough to 1/8" thickness, cut 24 rounds with a 4" cutter, and reroll scraps once for best yield.

Place 1–2 tablespoons of filling on 12 rounds, brush edges with egg wash, top with remaining rounds, seal with a fork, dock slits, and egg-wash tops.

Bake for 12–15 minutes until edges are golden and filling is just set, rotating sheets halfway through for even baking.

Let hand pies rest on the sheet for 5 minutes, transfer to a rack, dust with powdered sugar or drizzle glaze, and enjoy warm or at room temperature.