1-First Step: Activate the yeastDissolve 2 1/4 teaspoons active dry yeast in 3/4 cup lukewarm milk and let it sit for about 5 minutes. The mixture should look foamy. That foam is a good sign that the yeast is alive and ready to help the batter rise. If the mixture stays flat, the milk may have been too hot or too cold, and it is best to start again.

2-Second Step: Mix the batterIn a large bowl, combine 2 cups all-purpose flour, 2 teaspoons granulated sugar, and 1 teaspoon salt. Make a well in the center, then add the foamy yeast mixture, 1 egg, 1 teaspoon vanilla extract, and 1 tablespoon melted butter. Stir until the batter is smooth and slightly sticky. It should be thicker than pancake batter but still soft enough to drop by spoonfuls.

3-Third Step: Let the batter riseCover the bowl with a clean towel and set it in a warm place for 45 minutes. During this time, the batter should puff and become lighter. This resting period helps build the airy interior that makes Belgian croustillons so appealing. If your kitchen is cool, place the bowl near a warm oven or inside an oven that is turned off but lightly warmed.

4-Fourth Step: Heat the oilPour enough vegetable oil into a deep pot or fryer so the croustillons can float freely. Heat the oil to 350°F (180°C). A thermometer is the best way to check the temperature, but you can also test it by dropping in a tiny spoonful of batter. It should sizzle right away and rise to the surface quickly.

5-Fifth Step: Fry in small batchesUse a spoon or small ice cream scoop to drop portions of batter into the hot oil. Work in small batches so the temperature stays steady. Fry each batch for 3 to 4 minutes, turning them occasionally with a slotted spoon until all sides are golden brown and the croustillons look puffed. Small batches matter because crowded oil cools down fast and can leave the dough balls greasy instead of crisp.

6-Sixth Step: Drain and sugarLift the fried dough balls out of the oil and place them on paper towels to drain. While they are still warm, dust them generously with powdered sugar. Warm croustillons hold the sugar better, giving them that classic snowy finish people expect at Belgian markets and festivals.

7-Final Step: Serve right awayServe Belgian croustillons immediately while the outside is crisp and the inside is soft. They are at their best fresh from the fryer, when the contrast in texture is most noticeable. If you want to offer dipping options, set out chocolate sauce, caramel, whipped cream, fruit preserves, or honey so everyone can choose their favorite topping.