1-Step 1: Mix the dry ingredients In a large bowl, combine the flour, sugar, salt, and active dry yeast. Mix them well so the yeast and salt are spread evenly through the flour. This helps the dough rise more evenly later.

2-Step 2: Add the wet ingredients Pour in the lukewarm milk, then add the egg, vanilla extract, and melted butter. Stir until you get a thick batter. It should be soft and sticky, not dry like bread dough. If you are making the recipe for the first time, do not worry if it looks rough at this stage.

3-Step 3: Let the dough rise Cover the bowl with a clean kitchen towel or plastic wrap and let it rest in a warm place for about 1 hour, or until doubled in size. The batter should look bubbly and airy. This rise is what gives Belgian croustillons their light, fluffy middle. The waiting time matters. A good rise is what turns simple batter into crisp, puffy Belgian fritters.

4-Step 4: Heat the frying oil Pour enough vegetable oil into a deep pot or heavy pan to allow the dough balls to float. Heat the oil to 175°C or 350°F. If you do not have a thermometer, drop in a tiny bit of batter. It should sizzle and rise right away, but not burn fast.

5-Step 5: Shape and fry the croustillons Use two spoons or a small cookie scoop to drop spoonfuls of batter into the hot oil. Work in small batches so the oil temperature stays steady. Fry the dough balls for 2 to 3 minutes per side, turning them gently until they are deep golden brown.

6-Step 6: Drain and dust Lift the croustillons out with a slotted spoon and place them on paper towels to drain. While they are still warm, dust generously with powdered sugar. Serve them right away for the best texture.

7-Step 7: Serve while warm Belgian croustillons are at their very best fresh from the fryer. The outside stays crisp, and the inside stays soft and fluffy. If you want a special dessert spread, serve them with coffee, hot chocolate, or fresh fruit.