Preheat oven to 350ºF. 12 cup muffin tin with paper liners
In a small bowl combine oats with buttermilk; let stand 10 min.
In a medium bowl, with an electric mixer, beat cream cheese, granulated sugar and zest until blended; set aside.
Mix flour, brown sugar, baking powder, baking soda and salt in large bowl.
Add egg and butter to oat mixture; stir until well blended. Add to dry ingredients; stir just until moistened. Gently stir in berries.
Spoon half the batter evenly into 12 muffin cups lined with extra-large or giant paper liners, filling each liner half full; top each with 2 Tbsp. cream cheese filling. Cover with remaining batter.
Bake at 350 degrees for 25 to 27 min. or until toothpick inserted in centers comes out clean.