Toss the broccoli florets with the oil and seasoning and arrange on a large baking sheet. Use two if the pan is too crowded to prevent steaming.
Add the garlic cloves, whole and unpeeled, to the baking sheet.
Bake for 20-30 minutes. Stir the broccoli at the 15 minute mark and check the garlic, if it's very soft already (like custard) then take it from the oven, if it's still firm, leave it in with the broccoli.
When the broccoli has finished roasting and the garlic is very soft, melt the butter.
Squeeze the roasted garlic cloves into the butter and mix well.
Toss the broccoli with the garlic butter and serve.
Notes
*If you only have thin or small cloves, use closer to 6, and note that they'll get soft much faster, so they may be very soft earlier in the cook time. Remove them once they are to prevent burning. *I used my all-purpose seasoning, which is much less salty than traditional seasoning salt. If you're using a store bought seasoning salt, reduce by half, taste a floret and add a little more to your tastes. To make my all purpose seasoning just for this recipe, use this ratio: 3/4 teaspoons kosher salt, 1/2 teaspoon black pepper, 1/4 teaspoon smoked paprika, 1/4 teaspoon garlic powder, 1/4 teaspoon onion powder, and a shallow 1/2 teaspoon of granulated sugar.