Steps
1. Preheat the oven to 180°C (350°F).
2. In a bowl, combine flour, sugar, baking powder, and salt.
3. Add softened butter and mix until crumbly.
4. Beat the egg with vanilla extract and add to the dry ingredients; knead until a smooth dough forms.
5. Wrap the dough in plastic and refrigerate for 30 minutes.
6. Meanwhile, prepare the filling: grind the poppy seeds finely.
7. Mix ground poppy seeds with sugar, honey, milk, lemon zest, and vanilla extract until well combined.
8. On a floured surface, roll out the dough to about 3 mm thickness.
9. Cut out circles approximately 8 cm in diameter.
10. Place 1 tsp of the poppy seed filling in the center of each circle.
11. Fold the edges to form a triangle, pinching the corners tightly to seal.
12. Place hamentaschen on a baking sheet lined with parchment paper.
13. Bake for 15 minutes or until golden brown.
14. Let cool before serving.