Paul Prudhomme’s Cajun Meatloaf has a little heat with cayenne and Tabasco in it, but it may be a bit "soupy" for cooking on the grill (if that is what you intend). You can find the recipe online.
But no matter what meatloaf you make, you can serve it with Prudhomme's Very Hot Cajun Sauce for Beef, and it will be hot as Hades. It takes some time to make, but it packs a ton of flavor. You can dial the heat up or down as desired.
Even with just the basic 1/4 cup of minced jalapeno pepper, it is plenty hot.
Very Hot Cajun Sauce for Beef
3/4 cup chopped onion
1/2 cup chopped green bell pepper
1/4 cup chopped celery
1/4 cup vegetable oil
1/4 cup all-purpose flour
1 tablespoon all-purpose flour
3/4 teaspoon ground red pepper -- (preferably cayenne)
1/2 teaspoon white pepper
1/2 teaspoon black pepper
2 bay leaves
1/4 cup minced jalapeno pepper
1 teaspoon minced garlic
3 cups beef stock
Note: Fresh jalapenos are preferred; if you have to use pickled ones, rinse as much vinegar from them as possible.
Combine the onions, bell peppers and celery in a small bowl and set aside.
Make a roux as follows: In a heavy 2-quart saucepan heat the oil over medium-low heat to about 250 degrees. With a metal whisk, whisk in the flour a little at a time until smooth. Continue cooking, whisking constantly, until roux is light brown, about 2 to 3 minutes. Remove from heat and with a spoon immediately stir in the vegetable mixture and the red, white and black peppers; return pan to high heat and cook about 2 minutes, stirring constantly.
Add the bay leaves, jalapeno peppers and garlic, stirring well. Continue cooking about 2 minutes, stirring constantly. The mixture should be pasty. Remove from heat.
In a separate 2-quart saucepan, bring the stock to a boil. Add the roux mixture by spoonfuls to the boiling stock, stirring until dissolved between each addition. Bring mixture to a boil, then reduce heat to a simmer and cook until the sauce reduces to 3 1/2 cups, about 15 minutes. Skim any oil from the top and serve immediately.