Preheat oven to 325°F. Line two baking sheets with parchment paper and set aside.

In a large bowl, cream together the butter and powdered sugar until light and fluffy, about 3 minutes. Beat in the egg, oil, lemon zest and vanilla and stir until smooth

In a separate bowl, whisk together the flour, poppy seeds and salt. Gradually beat into the butter mixture until well combined.

Shape the dough into 1-inch balls and place onto the prepared baking sheets, about 1-inch apart. Press a deep indentation in the center of each with the end of a wooden spoon handle. Fill with the lemon curd.

Bake until lightly golden brown, about 10 to 12 minutes. Remove from the oven and allow to cool for 10 minutes in the pan before transferring to a wire rack to cool completely. Store leftovers in an airtight container, at room temperature, for up to 3 days. Or you can freeze cookies, layered between waxed paper, in freezer containers. Thaw before eating. Enjoy!