- Preheat oven to 325°F and line two large baking sheets with parchment paper.
- Place softened butter in the bowl of an electric mixer fitted with the whisk attachment. Whip on medium-high speed, for approximately 8 minutes, scraping the sides of the bowl every few minutes, until the butter is fluffy and has doubled in size.
- Add the sweetened condensed milk and whip until blended.
- Swap out the whisk attachment for the paddle attachment and add the flour and baking powder. Slowly combine until a semi-soft dough forms, about 2-3 minutes.
- Divide the dough evenly between 4 bowls.
- Assign a flavored gelatin to each bowl. Sprinkle each bowl with 2 tablespoons of the desired color and flavor and, using a fork or your hands, knead until blended.
- Using a small scoop (or tablespoon measure), portion the dough, and place, spaced 2-inches apart, on the prepared baking sheets.
- Place in the oven and bake for 12-15 minutes or until cooked through and just starting to lightly brown on the bottom. Remove from the oven and set aside to cool on a wire rack.