I followed this recipe:
https://scientificallysweet.com/soft-sprinkle-sugar-cookies/#recipe
Ingredients
¾ cup (170g) unsalted butter, softened
½ cup plus 1 tbsp (115g) granulated sugar
½ cup (110g) packed light brown sugar
1 ½ teaspoon (7ml) pure vanilla extract
1 large egg, at room temperature
1 large egg yolk, at room temperature
1 tablespoon (15ml) whole milk, at room temperature
2 cups (284g) all-purpose flour
¾ teaspoon baking powder
½ teaspoon baking soda
½ teaspoon salt
½ cup (80g) rainbow jimmies sprinkles (sprinkle rods)
3 tablespoon (40g) granulated sugar for rolling (optional)
3 tablespoon rainbow confetti sprinkles for rolling (optional)
Instructions
Make the cookie dough. Combine soft butter with both sugars and vanilla in a large bowl and mix with an electric hand mixer on medium-high speed for 1-2 minutes until pale and fluffy. You can also mix by hand using the creaming method with a wide rubber spatula. Add the egg and mix until well incorporated and smooth, then mix in egg yolk and milk.
Combine flour, baking powder, baking soda and salt in a medium bowl and whisk to blend evenly. Add these dry ingredients to the butter/sugar mixture and fold it in until mostly combined with a few streaks a flour remaining. Add sprinkles and fold them in until evenly combined. Cover the bowl and refrigerate for 1 hour.
Preheat your oven to 350°F. Line two large cookie sheets with parchment paper.
Bake the cookies. Use a 1.35-oz cookie scoop to portion dough and roll into smooth balls, then roll the dough balls in granulated sugar so they are evenly coated. Sometimes I skip this step and press the top of the dough balls in confetti sprinkles instead.
Place the dough balls onto prepared baking sheets spacing them at least 3 inches apart with room to spread. Bake for 9-12 minutes until puffed and the edges are just lightly golden and the bottoms are lightly browned. The centers will puff up and still feel slightly soft in the middle. They will deflate slightly as they cool. Transfer baking trays to a wire rack to cool for 2 minutes then transfer cookies individually to a wire rack to cool completely
BTW I should mention that I forgot to add the light brown sugar when creaming the butter and sugars together and only added it after mixing in the milk and eggs. I also forgot to add vanilla extract as well and only added it while mixing the wet and dry ingredients.
Although they are still soft and chewy, I want them to look like the ones from the photos online.