Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper or silicone baking mats.

1. In a medium bowl, whisk together the flour, baking soda, baking powder, and salt. Set aside.
2. In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.
3. Add the egg, vanilla extract, orange zest, and orange juice. Beat until well combined.
4. Gradually add the dry ingredients to the wet mixture, mixing until just combined. The dough should be soft but not sticky.
5. Roll the dough into balls about 1 inch in diameter and place them on the prepared baking sheets. Use the bottom of a glass or your hand to gently flatten each ball into a round shape.
6. Bake for 8-10 minutes or until the edges are lightly golden. The centers should still look soft but will firm up as they cool.
7. Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.
8. For the frosting: In a large bowl, beat the softened butter until creamy and smooth.
9. Gradually add the powdered sugar, orange juice, orange zest, vanilla extract, and a pinch of salt. Beat until the frosting is smooth and fluffy.
10. Once the cookies have cooled, spread a generous layer of frosting on top of each cookie.