Beat eggs and sugar together with a pinch of salt, when you get a fluffy white mass, add sour cream, melted butter and vanilla. Beat again.
Sift flour, cocoa, baking soda and baking powder in a separate bowl, mix, and then sift these dry ingredients into the egg mixture, mix with a hand whisk.
Add 130 g chocolate chips and mix. Fill 2/3 of the muffin molds with batter. I lined molds with paper liners, so I didn't grease them, if you're baking in a metal pan, grease them.
Sprinkle the rest of the chocolate chips on top, and bake in the oven heated to 180 °C for 15-18 minutes. Check with a toothpick, if it comes out dry, it is ready.Bon Appetit!
