In a medium bowl, mix together whole wheat pastry flour, baking powder and salt. Set aside.
In a stand mixer or a large bowl with a hand mixer, cream together butter and maple syrup on medium high speed until light and fluffy. Add egg and vanilla extract, mixing on medium speed until combined.
Slowly add flour mixture to wet ingredients and mix on low speed, until just combined. Dough should be soft, but not sticky. Add a little more flour if it seems too sticky, 1 teaspoon at a time.
Wrap dough in plastic wrap or place the entire bowl in the fridge and let dough chill in the fridge for at least 1-2 hours, or overnight.
When dough is chilled and you’re ready to bake, preheat the oven to 350ºF, line baking sheet with parchment paper and set aside.
Remove dough from fridge and let it sit at room temperature for a few minutes to soften slightly. On a clean rolling surface (or a parchment lined surface) sprinkle 1-2 Tablespoons of flour on surface and rolling pin. Roll out dough, using a rolling pin, until it's about 1/4-1/3″ thick. The thicker your cookies are the softer they’ll be.
Use your favorite cookie cutter shapes to cut out the dough and place them about 1 inch apart on your cookie sheet. Gather and re-roll the dough scraps as many times as needed until all the dough is used. Add additional flour to the surface and rolling pin as needed to prevent the dough from sticking.
Bake for 8-10 minutes or until the edges and bottoms are lightly golden.
Allow cookies to cool a few minutes before transferring to a wire rack to cool completely.
Once cookies are cool you can frost and decorate them. To make homemade icing, combine powdered sugar, vanilla and almond milk in a small bowl. Whisk until all lumps of sugar have dissolved and icing is the thickness you desire. You don't want it to be super thick, but also don't want it to be too runny where it melts off the cookies. Frost cookies with icing and add sprinkles right away, before the icing has a chance to set.