Heat a saucepan over medium heat and add the condensed milk, passion fruit juice, butter, powdered milk, and egg yolk. Stir constantly with a wooden spoon for about 10-12 minutes until the mixture thickens and pulls away from the sides of the pan.

Transfer the mixture to a plate or bowl and let it cool completely before handling.

Grease your hands lightly with butter or oil and roll small portions of the dough into bite-sized balls.

Roll each ball in crystal sugar to coat.

Place the brigadeiros on paper cupcake liners and serve at room temperature.

Use high-quality passion fruit juice for the best flavor. Don't skip the cooling step; it's essential for shaping the brigadeiros. If the dough feels too sticky, chill it for a few extra minutes. For variations, consider adding a splash of vanilla extract or a pinch of salt for enhanced flavor. Store the brigadeiros in an airtight container, and they can last up to a week in the fridge or 3 months in the freezer.