How to Make It
Preheat oven to 375°F. Coat 12 muffin cups with cooking spray.
To prepare filling, combine pecans and next 4 ingredients (through salt) in a small bowl; toss to combine. Add buttermilk and butter, stirring until smooth.
To prepare muffins, weigh or lightly spoon flour into dry measuring cups; level with a knife. Combine flour and next 4 ingredients (through baking soda) in a bowl; stir with a whisk. Place 3/4 cup buttermilk and next 4 ingredients (through eggs) in a large bowl; beat with a mixer at high speed for 2 minutes. Add flour mixture to buttermilk mixture; 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 wooden pick inserted in center comes out clean. Cool in pans 10 minutes on a wire rack; remove from pans.
Combine yogurt, powdered sugar, and cream cheese, stirring well with a whisk. Drizzle over muffins.