Combine the cinnamon and sugar in a small shallow bowl. Rub the rims of 2 large or 4 small glases with a little water (coconut rum or tequila would work too). Dip the rims through the cinnamon sugar. Place the glasses in the freezer.

To a blender add 2 churros (adding more if you want an extra cinnamony flavor. I used 4 churros, but it was a little intense. So good, but a little intense), ice cream, milk, vanilla extract, coconut rum or tequila if using and 2 tablespoons warm dulce de leche. Blend until your desired consistency is reached. If you do not want chunks of churros blend until completely smooth.

Remove the glasses from the freezer and drizzle with warm dulce de leche on the insides and bottoms of the glasses. Pour in the milkshake and garnish each with a churro...or two. Bottoms up.