Preheat oven to 350 degrees F (175 degrees C). Grease cookie sheets.
In a large bowl, beat the eggs, evaporated milk, oil and vanilla until well blended.
Mix in the sugar and baking powder. Stir in the flour 1 cup at a time until the dough becomes too stiff to stir. Turn out onto a clean surface and knead in as much of the remaining flour as possible. Dough should be smooth and not sticky. Keep the dough covered with a towel while pinching off tablespoon sized pieces of dough and rolling them into small ropes 6 inches long and 1/4 inch in diameter. Tie ropes into loose knots and place them 2 inches apart onto the prepared cookie sheets. The cookies will almost triple in size while baking.
Bake for 10 to 12 minutes in the preheated oven, until light brown on the bottom.
Remove from cookie sheets to cool on wire racks. When cool, glaze with a mixture of confectioners' sugar and water, if desired.
