Preheat oven to 375°F. Line 12 muffin cups with paper liners.
To prepare filling, combine pecans, sugar, cinnamon, vanilla and salt in a small bowl; toss to combine. Add kefir and coconut oil stirring until smooth.
To prepare muffins, spoon flour into measuring cup and level with a knife. Combine flour, baking powder, cinnamon, salt and baking soda in a bowl; stir to combine.
Place kefir, sugar, coconut oil, vanilla and eggs in a large bowl; beat with a mixer at high speed for 2 minutes. Add flour mixture and stir just until combined.
Place 1 tablespoon batter in each muffin cup. Top evenly with filling. Spoon remaining batter over filling.
Bake at 375°F for 15 minutes or until a skewer comes out clean. Cool in pan for 10 minutes on a wire rack, then remove from the pan and allow to cool.