In a small bowl, whisk together the 1 ½ cups all-purpose flour, 2 teaspoons cornstarch, ¾ teaspoon baking soda, and a pinch of salt. Set aside.
To the bowl of a stand mixer fitted with the paddle attachment, combine together on medium-high speed the ½ cup butter, ¾ cup granulated or cane sugar, 1 large egg, 1 ½ teaspoons vanilla extract, and 1 ½ teaspoons almond extract. Continue mixing on medium-high until light and fluffy. You may also use a hand mixer instead.
Stop the mixer and scrape down the sides of the bowl, turn the mixer on low speed, and slowly add the flour mixture. Mix until combined, about 1 minute.
Add in the ¼ cup rainbow sprinkles and mix for a few seconds to distribute throughout the cookie dough.
Using a cookie scoop, form the cookie mounds and place them on a large plate or baking sheet covered with plastic wrap. Refrigerate the cookie dough for at least 2 hours and up to 5 days before baking.
Once you are ready to bake. Line a large baking sheet with parchment paper and preheat the oven to 350 degrees F. Bake the cookies for 4 minutes, rotate the tray, and continue to bake for an additional 4 minutes.
Remove the funfetti cookies from the oven and allow them to cool for at least 5 minutes on the baking sheet before transferring them to a cooling rack to cool completely. Enjoy!
Store the funfetti sugar cookies in an airtight container at room temperature for up to 5 days.