Using a stand or hand mixer, beat 1 cup room temperature butter and ¾ cup granulated sugar in a mixing bowl on high speed for about 5 minutes until its light and fluffy.
Then add an egg and 1 tsp vanilla extract and beat again for 1-2 minutes or until well incorporated.
Scrape the sides of the bowl with a spatula a couple of times in-between of mixing, so all the ingredients are evenly distributed.
In a separate mixing bowl, add dry ingredients (3 cups all-purpose flour, 1 tsp baking powder, and ¼ tsp salt). Whisk and add to the wet ingredients in two steps. Mix on a low speed until well combined.
When done, slightly knead the dough with your hands, making a ball. Flatten it into a disk and wrap in plastic wrap. Refrigerate for at least 1-2 hours or overnight.
When you roll out the dough it might be a bit sticky. You can use a little bit of flour to prevent it from sticking to a roller or a counter. However, I have a different trick that always helps me. Put the dough between two sheets of parchment paper, then roll over the parchment paper about ¼-inch thick.
Cut out cookies with your favorite cookie cutter.
After you cut out the cookies and put them on the baking sheet, put the sheet with the cookies back in the fridge for 10 minutes to chill.
Bake the cookies at 350°F for 9-10 minutes or until the edges are slightly golden and the tops are just set but still soft.
When done, take the cookies out of the oven and let them sit on the counter on the baking sheet for about 10 minutes. Then transfer to a wire rack to cool off completely.