Churros donuts

Ingredients:
1 ½ cup water; 2 ½ tbsp. sugar; 2 tbsp vegetable oil; 1 cup flour; vegetable oil for frying; hazelnut paste; cinnamon sugar.
Instructions
Mix water, sugar and vegetable oil in a small pot. Bring the mixture to boil while whisking constantly. Add flour and combine everything until a smooth ball of dough forms. Put the dough into a pastry bag with a small star-shaped tip. Squeeze the dough on a piece of parchment paper to form circles. Freeze churros completely. Heat vegetable oil to 180C (350F). Fry churros for 2-3 minutes on both sides or until crispy and golden. Cover each churro with cinnamon sugar, put about a teaspoon of hazelnut paste on half of them and cover with another half to make a sandwich.