In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
In a large bowl, using a handheld mixer or stand mixer fitted with a paddle attachment, beat the butter and sugar on high speed until light and creamy, about 3 minutes.
Add the egg, vanilla, and almond extract if using, and beat on high until fully combined, about 1 minute.
Scrape down the sides and bottom of the bowl and beat again to incorporate everything.
Add dry ingredients to wet ingredients and mix on low speed until just combined. The dough should be soft.
If too soft and sticky, beat in an additional tablespoon of flour.
Divide dough into two equal portions and place each on lightly floured parchment paper or silicone mats.
Roll dough to about 1/4-inch thickness, adding flour if sticky.
Dust one rolled dough with flour, place the second rolled dough on top, cover tightly and refrigerate for at least 2 hours or up to 2 days.
Preheat oven to 350°F (177°C) and line baking sheets.
Remove top dough from fridge, loosen if sticking.
Cut dough with cookie cutters into desired shapes.
Gather scraps, reroll and cut more cookies.
Arrange cookies 3 inches apart on baking sheets.
Bake for 11 to 12 minutes until edges are lightly browned and set.
Rotate baking sheets halfway if oven has hot spots.
Cool cookies on sheets for 5 minutes, then transfer to wire rack.
Decorate cooled cookies with icing and sprinkles.
Refrigerate sheet of decorated cookies to help icing set faster.
Store cookies covered at room temperature for up to 5 days or in fridge for up to 10 days.
If decorated with buttercream, keep covered at room temperature up to 1 day or refrigerated up to 5 days.