Preheat your oven to 400°F (200°C). Gather all your ingredients and equipment.

In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, salt, and baking powder until well combined.

Add the cold, cubed unsalted butter to the dry mixture and blend until the texture resembles coarse crumbs.

In a separate bowl, whisk together the large egg, whole milk, and vanilla extract until smooth. Gradually pour this into the dry ingredients and stir gently until just combined.

Turn the dough onto a lightly floured surface and knead gently. Roll it out to a thickness of 1/2-inch.

Using a 2-inch round cookie cutter, cut out circles from the rolled dough and place them on the prepared baking sheet.

Bake for 12 to 15 minutes, or until lightly golden on the edges.

Transfer the tea cakes to a wire rack to cool completely and dust with powdered sugar before serving.