Preheat oven to 400 degrees. Line 12 muffin cups with cupcake liners, or lightly coat the muffin cups with nonstick cooking spray.
Add the corn flakes and milk to a large bowl, and let them sit for 3-5 min or until cereal softens, stirring once or twice.
Stir in the egg, vegetable oil, and vanilla, mixing well with a rubber spatula or a wooden spoon.
In a medium bowl, combine and whisk the flour, sugar, baking powder, and salt together. Gradually add to the cereal mixture. Note: the batter will be stiff.
Divide the batter evenly between the prepared muffin cups. Using the back of a wooden spoon or your finger, make a deep indentation in the center of each, and fill the well with about 1 teaspoon of jam.
Bake at 400° for 18-21 min, or until lightly golden brown and a toothpick inserted into the muffin part comes out clean.
Cool in the pan for 5 min before removing to a wire rack to cool completely.
Store in a covered container or place in a large resealable plastic bag and freeze.