Preheat oven to 350 degree F and line baking sheets with parchment paper or silpat mats.
With an electric mixer in a large bowl or in the bowl of a stand mixer, cream together the butter and sugar until light and fluffy. Add the egg, orange juice, orange zest and vanilla extract. Beat until combined.
Add the flour, baking soda and baking powder. Continue to mix together until cookie dough is formed, scraping down the sides of a bowl with a spatula occasionally. Do not over-mix.
With a large cookie scoop or ice cream scoop, equivalent to 1/4 cup, scoop cookie dough into balls and place on the prepared cookie sheets.
Bake for 10-12 minutes or just until the edges turn a light golden brown. Let cool for a few minutes before transferring to a wire cooling rack. Enjoy!
While the cookies cool, in a medium or large bowl, whisk together the melted butter, powdered sugar, orange juice and zest. Add more powdered sugar if the icing is too thin, and a splash of milk if it's too thick.
Once the cookies have cooled, spoon, drizzle or dip each cookie in the icing and place on cooling rack to dry and set, enjoy!