01 - In a medium bowl, whisk together the all-purpose flour, baking powder, and salt until evenly combined.
02 - In a large bowl using an electric mixer, beat the softened butter and granulated sugar together until light and fluffy, approximately 2 to 3 minutes. Add the egg, orange juice, vanilla extract, and orange zest, then beat until the mixture is smooth and well incorporated.
03 - Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until a soft, cohesive dough forms. Flatten the dough into a disk shape, wrap tightly in plastic wrap, and refrigerate for at least 1 hour to firm up.
04 - In a small bowl, combine the softened cream cheese, powdered sugar, orange zest, orange marmalade, and vanilla extract. Stir until completely smooth and no lumps remain. Set aside.
05 - Preheat the oven to 350°F. Line two baking sheets with parchment paper and set them aside.
06 - On a lightly floured surface, roll the chilled dough out to an even 1/8-inch thickness. Using a 3-inch round cookie cutter, cut out circles and place them on the prepared baking sheets. Re-roll scraps as needed.
07 - Place 1 teaspoon of the creamsicle filling in the center of each dough circle. Fold the edges upward to form a triangle shape, pinching the three corners firmly to seal them together.
08 - Space the shaped cookies about 1 1/2 inches apart on the prepared baking sheets to allow for slight spreading during baking.
09 - Bake for 12 to 14 minutes, or until the edges are lightly golden. Allow the cookies to cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely before serving.