To begin, pour the warm water into a small bowl and stir in the sugar and dried yeast. Leave for 8 to 10 minutes until the surface becomes foamy, then move on to mixing the dough.
Place the flour and salt into a large bowl and mix well. Make a well in the centre, pour in the activated yeast mixture and sunflower oil, then begin bringing the dough together with a wooden spoon before moving to hand mixing.
Turn the dough onto a lightly floured surface and knead for about 8 minutes until smooth and elastic. The dough should feel soft but not sticky. Once ready, return it to the bowl to begin resting.
Cover the bowl with a clean cloth and leave the dough in a warm place for 60 to 75 minutes, or until doubled in size. Proper fermentation gives lángos its signature lightness, so do not rush this step.
Gently knock back the risen dough and divide it into four equal portions. Shape each into a loose ball, cover again, and allow them to rest for 15 minutes before shaping.
Using lightly oiled hands, stretch each dough ball into a rough disc about 18 to 20 cm wide. Keep the centre slightly thinner than the edges to ensure even frying, then prepare the oil.
Heat sunflower oil in a deep pan to 170°C. Carefully lower one disc into the oil and fry for 2 to 3 minutes per side until golden and puffed. Transfer to kitchen paper and repeat with remaining dough.
Mix the crushed garlic with warm water. While the lángos is still hot, brush lightly with the garlic mixture so it absorbs without overpowering the bread.
Serve immediately topped with sour cream and grated cheese. Lángos is best enjoyed hot, with extra garlic sauce or pickled vegetables on the side for balance and contrast.