1. Combine first 6 ingredients in a large bowl; make a well in center of mixture.
2. Whisk together buttermilk, oil, and eggs; add to dry mixture, stirring just until moistened. Gently fold in grated orange rind, marmalade, and cranberries. Spoon batter into a lightly greased muffin pan, filling two-thirds full.
3. Bake at 375° for 16 to 18 minutes or until golden brown. Cool in pan on wire rack 5 minutes; remove from pan to wire rack, and cool 10 minutes or until completely cool.
Note: For testing purposes only, we used Post Grape-Nuts cereal.