Whisk together the flour, baking powder and salt in a small bowl and set aside. In a large bowl, combine the butter, sugar, honey, egg and vanilla extract. Add the buttermilk and mix until combined. Add the dry ingredients and mix until just combined – make sure not to overmix. Dye the batter green with the food coloring.
Spoon the batter into a piping bag, then pipe the batter into a greased doughnut pan and bake at 400F for 7 minutes. Cool for 1 minute in the pan, then flip the pan over to remove the doughnuts and cool completely on a wire rack.
Beat the butter with an electric mixer at room temperature until light and fluffy. Add the vanilla extract and beat until combined. Add the confectioner’s sugar one cup at a time, then beat for 3 minutes, until fluffy. Dye ¼ cup of the frosting red and the remaining frosting green.
Place the red frosting into a piping bag fitted with a small, round piping tip. Place the green frosting into a piping bag fitted with a small, star-shaped piping tip.
Pipe the green frosting onto the doughnuts to look like pine needles and create a bow with the red frosting. Decorate with holiday sprinkles and enjoy!