Hamantaschen are traditional triangular-shaped cookies that are commonly associated with the Jewish holiday of Purim. The name "Hamantaschen" translates to "Haman's pockets" or "Haman's ears" in Yiddish and Hebrew.
Preheat the oven to 350 degrees F (175 degrees C). Lightly grease cookie sheets.
Combine eggs and sugar in a large bowl; beat with an electric mixer until smooth and creamy. Stir in oil, orange juice, and vanilla. Combine flour and baking powder; stir into batter to form a stiff dough, adding more flour if needed.
Turn dough out onto a lightly floured surface and roll out into a 1/2-inch thickness. Cut into circles using a cookie cutter or the rim of a drinking glass; place 2 inches apart onto the prepared cookie sheets. Spoon about 1 to 2 teaspoons of preserves into center of each cookie. Pinch edges to form three corners.
Bake in the preheated oven until lightly browned, 12 to 15 minutes. Cool on the cookie sheets for 1 minute; transfer to a wire rack to cool completely.
Notes
Chill the Dough: If the dough becomes too soft or sticky while working with it, you can chill it in the refrigerator for about 30 minutes to make it easier to handle.
Flour the Surface: When rolling out the dough, make sure to lightly flour the surface and rolling pin to prevent sticking.
Uniform Thickness: Try to roll the dough out to a uniform thickness so that the cookies bake evenly.
Sealing the Edges: Ensure that the edges of the Hamantaschen are firmly sealed to prevent the filling from leaking out during baking.