Several more ideas....
Mashed potatoes with add ins - Michael Chiarello did a show in this with his daughters years ago so we did this with my daughter and her friends and they thought it was great - he had pesto, other veggies like carmelized onions - all sorts of stuff you can prep in advance and just sit out.
Pies - cornish pasties or stromboli, etc. Just take a premade dough and roll them out into rounds. Let the kids stuff them and bake them. Thinly sliced potatoes, beef, onions, other veggies are the base for Cornish Pasties and then peppers, sausage, ground beef, chicken, cheeses, pepperoni, with marinara, alfredo, pesto for more of an Italian style hand held meat pie. Do like they did on Cornish pasties and have a little extra dough that the kids roll out and apply to the top to 'mark' their pie. And you can do like some bakers and put meat in one end and dessert in the other.
Also baked potato bar - chili, stroganoff, cheese, veggies, bacon, taco, bbq
Pasta bar
Depending on how many boys you have - this is fun but can be labor intensive since you have to do the frying - egg rolls - have traditional ingredients as well as some other stuffings - I saute a little chinese cabbage or napa with some veggies as a base. Then I have pork, chicken and shrimp, water chestnuts, snow peas, bean sprouts and such for the oriental style ones. Then seasoned ground beef and chicken, beans (refried or not), cheese, salsa, corn, peppers and such for Southwestern style ones. Pulled bbq, white or baked beans, slaw, and cheese for 'Southern BBQ' style ones. Some fruit and fillings like cream cheese sweetened and flavored, marshmallow cream, peanut butter, and such for dessert egg rolls. Just make sure to drain as much liquid off things as possible before putting into egg roll wrappers to avoid grease popping.
Pretzels are fun to make and have different toppings and dips.
With this weather - salads - taco, frito pie, just all sorts of toppings to make their own.
Homemade ice cream with mix-ins - a friend did this recently with her boys and they all had a blast. Seems that making ice cream is a forgotten simple pleasure and the kids had a blast - I don't think most of them had ever seen it done. She had canned cherries, the magic shell, carmel, choc chips, all sorts of fruit, marshmallow cream, nuts, chopped up candy bars and off course to top it off - the whipped cream in the can!