Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the room temperature butter and granulated sugar. Beat them together on medium speed until light and fluffy, about 2-3 minutes.
Add the large egg and almond extract to the mixture and mix until well combined.
In a separate bowl, whisk together the all-purpose flour, baking powder, baking soda, and kosher salt.
Gradually add the dry ingredients into the wet mixture, mixing on low speed until just combined.
Fold in the sliced almonds using a spatula.
Scoop out portions of the dough and roll into balls. Roll each ball in powdered sugar until completely coated.
Place the cookie balls onto a lined cookie sheet, leaving space for spreading. Bake for 10-12 minutes, or until the edges are lightly golden.
Let the cookies cool on the baking sheet for about 5 minutes before transferring to a cooling rack.
