In a bowl, combine room temperature butter with the sugar and cream. When it's mostly creamed, add 1/2 cup of the Nutella and mix well. Add vanilla and the eggs one at a time, beating between additions. Scrape sides of the bowl regularly.
3 tablespoons unsalted butter, 1/2 cup Nutella plus 2 tablespoons, 1 cup sugar, 2 eggs, 1 teaspoon vanilla
Add the baking powder, baking soda, salt, and cinnamon and mix well. Add 1 cup of flour and stir slowly. Add 1/2 the yogurt and mix until combined. Alternate a total of 3 flour additions and 2 yogurt additions, stirring slowly and mixing until just combined each time.
Using a small scoop, scoop out one dollop of batter into prepared muffin tins. Spread it just a touch with your spatula so that it mostly covers the bottom.
Using your 1/4 teaspoon measure, add a quarter teaspoon of Nutella to the middle of each dollop in the muffin tins.
Once they're filled with their special surprise, add a second, smaller dollop atop each cupcake to cover.
Bake at 350 degrees for 20-22 minutes, depending on your oven. When a cake tester comes out clean, they're done. Remove and let cool for five minutes before turning out onto a cooling rack to cool the rest of the way.