Preheat the oven to 350°F / 175°C.
Lightly spray a 9x13-inch baking dish with cooking spray. Set aside.
Place the sausage in a large skillet over medium heat.
Cook the sausage until it is fully browned and no longer pink, breaking it into crumbles as it cooks.
Drain any excess grease from the cooked sausage and set the sausage aside.
In a large saucepan, bring the chicken broth to a boil.
Slowly stir the quick cook grits into the boiling broth.
Reduce the heat to medium-low.
Cover the saucepan and cook the grits for 5 to 7 minutes, or until thickened, stirring occasionally.
Remove the saucepan from the heat.
Add the butter, cream cheese, cubed Velveeta cheese, drained Rotel tomatoes and green chilies, onion powder, garlic powder, milk, salt, and black pepper to the hot grits.
Stir until the butter and cheeses are fully melted and the mixture is smooth and evenly combined.
In a separate bowl, lightly beat the eggs.
Slowly stir the beaten eggs into the grits mixture until fully incorporated.
Add the cooked sausage to the grits mixture.
Stir until the sausage is evenly distributed throughout the casserole mixture.
Transfer the mixture to the prepared 9x13-inch baking dish.
Spread the mixture evenly in the dish using a spatula.
Bake, uncovered, for 40 to 45 minutes, or until the casserole is set and heated through.
Remove the casserole from the oven.
Allow it to rest for several minutes before serving.
Serve warm.