In a large bowl, mix the flour, baking powder and pinch of salt. This combination will become the dough base.
Add the butter cut into small pieces and mix until the mixture resembles breadcrumbs.
In another bowl, beat the egg and add it to the previous mixture. Gradually stir in the milk and water.
Knead the mixture on a floured surface until a smooth and elastic dough is obtained. Let it rest for a few minutes.
Divide the dough into small portions and stretch each one into a rectangular shape, similar to a ribbon.
Carefully place a line of Nutella along the center of each strip of dough.
Fold the dough over the Nutella, sealing the edges with your fingers or a fork to prevent the filling from escaping during frying.
Heat the oil in a frying pan and fry the tequeños until golden brown and crispy on the outside.
Remove the tequeños and place them on paper towels to remove excess oil. Ready to enjoy! Serve the Nutella Tequeños while they are hot and watch the chocolate filling melt in each bite.