Preheat your oven to 375°F and lightly grease a 9x13-inch baking dish with cooking spray or butter. Bring a large pot of salted water to a boil, then add fresh broccoli florets and cook for exactly 3 minutes until bright green but still crisp.

Drain broccoli thoroughly in a colander, then spread on a clean kitchen towel to remove excess moisture completely. This step prevents a watery casserole and ensures proper binding with the custard mixture throughout baking.

Melt butter in a large saucepan over medium heat, then add minced garlic and cook for 1 minute until fragrant. Whisk in heavy cream and chicken broth, stirring constantly for 2 minutes until the summer broccoli cheddar casserole crowd's base sauce thickens slightly.

Remove from heat and stir in shredded cheddar cheese, salt, black pepper, garlic powder, and cayenne pepper until completely melted and smooth. Beat eggs in a small bowl, then temper by slowly whisking in one cup of hot sauce while constantly stirring.

Pour the egg mixture back into the saucepan, whisking gently to combine without scrambling the eggs throughout the creamy mixture. Transfer blanched broccoli to your prepared baking dish, then pour the cheese custard over florets, stirring gently to distribute evenly.

In a small bowl, combine panko breadcrumbs with grated parmesan cheese and melted olive oil, mixing with a fork until crumbly. Sprinkle this topping evenly over the casserole, then bake for 35-40 minutes until the top is golden brown and a knife inserted in the center comes out clean.

Let the broccoli cheddar bake rest for 5 minutes before serving, which allows the custard to set properly. Garnish with fresh chopped parsley and serve warm alongside grilled meats or fresh summer salads.