Beat egg in bowl until fluffy. Beat in all ingredients, adding cranberry jelly last, until the batter is just smooth. (Add extra milk for thinner pancakes.)
Heat griddle or skillet over medium heat. Do not overheat the griddle as the jelly can burn.
For each pancake, pour about a 1/4 cup batter onto hot griddle. Cook pancake until bubbly, puffed up, and dry around the edges. Then turn pancake over and cook other side.