Hot dog fondue is a good one. Mix a small jar of currant, grape or apple jelly with a small jar of mustard in a saucepan and cook, stirring, until mixture jelly is melted. Simmer for a while, then add hot dogs that are sliced diagonally, and/or baby smoky links, cut in half. Continue to simmer for 20 minutes or so, then keep warm in a small crockpot or fondue pot.
Another thing they'll like: spread re-fried beans on a 10" flour tortilla, sprinkle liberally with cheese, and roll up. Brush tops with a little olive oil, then stick in a 350 oven and let cook until cheese is melted. Remove from oven and cut each roll into 2-3 pieces. Serve with a mild salsa.
Mini pizzas would also be fun. You can do them on pita bread or English muffins. Spread with a little tomato sauce, then add the toppings and stick in the oven. Most kids like cheese and pepperoni the best, but you could use most anything.
Finally, here's a recipe from my mother, who taught kindergarten for 30 years.
Finger Jello
4 tbls knox gelatin
1 tsp lemon juice
1 cup cold water
3 small packages jello
3 cups hot water
Combine first 3 ingredients and let set while preparing jello. Mix jello with hot water, then combine both mixtures. Pour into a pan and refrigerate until set up. cut out shapes with cookie cutters, or into squares.
Kids can eat these with their hands.