Make the Filling
Beat cream cheese, powdered sugar, and vanilla in a bowl until smooth and creamy. Let sit at room temperature for easier spreading.
Assemble the Sandwiches
Spread filling on 4 slices of bread, staying slightly away from the edges to prevent leaks. Top with remaining slices and press gently to seal.
Prepare the Custard
Whisk together eggs, milk, granulated sugar, vanilla, cinnamon, and a pinch of salt in a shallow dish until smooth.
Dip and Soak
Dip each sandwich into the custard, soaking 10–15 seconds per side so the bread absorbs the mixture without falling apart. Let excess drip off.
Cook the French Toast
Heat a nonstick skillet or griddle over medium heat and melt a little butter. Cook each sandwich for 3–4 minutes per side, pressing lightly until golden brown and custardy inside.
Churro Finish
Mix cinnamon and sugar in a shallow bowl. Brush the warm French toast with melted butter, then roll or press into the cinnamon-sugar mixture until generously coated on all sides. Serve hot