Begin by placing softened butter in a mixing bowl. Use an electric mixer on medium-high speed to beat the butter until it becomes light and fluffy, reaching a pale color, which should take about 3 minutes.

Gradually add the sweetened condensed milk to the creamed butter. Continue mixing for an additional 2 minutes, ensuring that the mixture is well combined and smooth.

In a separate bowl, whisk together the all-purpose flour and baking powder. Slowly add this dry mixture into the wet ingredients, mixing just until combined.

Using a small cookie scoop or your hands, form the dough into small, rounded mounds and place them on a parchment-lined baking sheet, leaving about 2 inches of space between each. Refrigerate the sheet for at least 30 minutes.

After chilling, remove the snowballs from the fridge. Lightly sift confectioners' sugar over each snowball for a festive finish. These can be served immediately or stored in an airtight container.