On a wax paper lined baking sheet, drop 15 round teaspoonfuls of Nutella (making sure they do not touch). Place the baking sheet in the freezer for at least 2-3 hours, or until the Nutella is frozen solid.
Preheat oven to 375 degrees F. Line 15 muffin cups with paper or foil liners and set aside.
In a large bowl combine the flour, baking powder, baking soda and salt. Whisk to combine, set aside.
Cream the butter and sugar in the bowl of your stand mixer until light and fluffy (2 min). Beat in one egg at a time, then add the vanilla. Scrape down the sides of the bowl.
Alternate adding the flour mixture and the yogurts to the butter mixture. (Batter will be really thick) Add the cup of mini chocolate chips, and stir them in.
Divide the mixture evenly into the prepared muffin tin (note: fill above the top of the cup). Remove the Nutella from the freezer and quickly push the frozen Nutella into the center of the muffins. Then sprinkle each muffin with the remaining chocolate chips and turbinado sugar.
Bake for 20-25 minutes or until the tops are golden brown. Best served slightly warm. Enjoy!