Mix 2 cups flour, 2 tbsp sugar, 1 tsp baking powder, and 1/2 tsp salt in a large bowl. Whisk until everything's combined—don't skip this step because the baking powder needs to be evenly distributed. Add 1 cup warm water, 2 large eggs, 1/4 cup melted butter, and 1 tsp vanilla extract. Stir until you get a thick, sticky dough that's kinda like cake batter. It should pull away from the bowl sides but still stick to your spoon.
Let the dough rest for 10 minutes at room temperature. This gives the flour time to fully hydrate and makes piping way easier. While you wait, grab a piping bag with a large star tip—this is the one tool that actually matters. Line a baking sheet with parchment paper because you're gonna pipe the dough onto it first.
Transfer your dough into the piping bag and pipe 2-inch pieces directly onto the parchment, spacing them about an inch apart. You'll hear the dough squeeze out with a satisfying sound as it fills the bag. Work quickly so the dough doesn't get too warm. Mine always sticks a little to the tip, and that's totally fine—just wipe it off between pieces.
Heat 1/2 cup vegetable oil in a shallow skillet over medium-high heat until it reaches 350°F. You can test it by dropping a tiny piece of dough in—it should sizzle immediately and float to the surface within 2 seconds. If it burns right away, the oil's too hot. If it just sits there, give it another minute to heat up.
Carefully transfer the piped dough pieces into the hot oil using a spatula or tongs. Don't crowd the pan—work in batches of 6 to 8 pieces so the oil temperature stays steady. They'll sink at first, then float. Let them cook for 2 minutes on the first side until golden brown, then flip and cook another 1.5 minutes on the second side.
When your kitchen smells like warm, buttery cinnamon with a hint of nutmeg, you know they're almost done. Transfer the fried bites to a paper towel–lined plate to drain excess oil. They'll cool for about 2 minutes—don't skip this or you'll burn your mouth and the sugar coating won't stick right.
Mix 1/2 cup sugar and 2 tbsp ground cinnamon in a shallow bowl with 1 pinch nutmeg. Toss the warm churro bites in the cinnamon sugar mixture until they're completely coated. Work in batches so the coating stays even. Serve immediately while they're still warm and crispy on the outside.