Grease muffin moulds with butter and dust with flour. Preheat your oven at 180C.
Fix in paddle attachment to a standing machine and cream butter and sugar.
Add in eggs and vanilla, beat on medium speed until light and fluffy. Now add buttermilk and scrape the sides.
Beat for few more seconds. Take another bowl and combine flour, salt, baking powder, cinnamon and nutmeg.
Fold in dry ingredients in wet ingredients and on low speed mix until all the ingredients get combined.
Take care not to overmix. Fold in chocolate chips. Add teaspoon of jam to muffin mould and top it with muffin batter. Fill upto ¾ of the mould consistency. Bake for 10-12 minutes.
Check by inserting a toothpick in the center of the muffin, if it comes out clean, then remove the muffins from oven and place them on wire racks.
Dust the top of donut muffins with sugar and cinnamon using a tea strainer.