Combine flour, water, milk, eggs, salt, vanilla, and cinnamon in a blender and puree until smooth.

Scrape down the sides of the blender jar if needed.

Add the melted butter and mix well.

Refrigerate batter in the blender jar for up to 1 hour.

Place a nonstick skillet over medium heat and brush with melted butter.

Pour about 3 tablespoons of batter into the hot pan using a ladle.

Tilt the pan to spread the batter thinly and evenly.

Cook until edges turn golden brown (about 2 minutes).

Flip the crepe with a wide spatula.

Cook the other side until lightly golden.

Place the crepe on a dish and cover with plastic to keep moist.

Repeat until all batter is used (about 12 crepes).

Butter the bottom of a 1-quart baking dish.

Place 2 tablespoons of dulce de leche in the center of each crepe.

Fold the crepe in half.

Fold it again to create a triangular shape.

Place the folded crepe in the prepared baking dish.

Repeat with remaining crepes, overlapping slightly.

Sprinkle 2 tablespoons of granulated sugar evenly over the crepes.

Caramelize the sugar with a blowtorch or under the broiler until golden brown (about 5 minutes under the broiler).

Garnish with confectioners' sugar.

Serve warm.