Wash the potatoes and place in a pot with cold, heavily salted water covering them. Bring to a boil and cook until tender and a knife slips easily into them, about 20 minutes.
Drain in a colander and allow to cool for 5-10 minutes.
Meanwhile, brush a rimmed baking sheet with 1 tablespoon of the olive oil.
Melt the butter (2 tablespoons) in the microwave and stir in the everything bagel seasoning.
Place the potatoes on the baking sheet and smash, carefully, using a potato masher, a fork, or the bottom of a drinking glass. Try to keep them in one piece, but if they crumble apart a bit, that's fine too.
Brush the remaining 1 tablespoon olive oil evenly on top of the smashed potatoes.
Brush the melted butter with everything bagel seasoning evenly on top of the smashed potatoes. Make sure to use ALL of it.
Bake for 30 minutes at 350 degrees, or until deeply golden.
Allow to cool for 5 minutes before removing from pan and eating.
You can probably get everything bagel seasoning already mixed at your grocery store (Trader Joe’s has it for sure- it's called "Everything But the Bagel"), or you can make your own.
The provided nutrition information does not include any added sodium from seasoning to taste, any optional ingredients, and it does not take brands into account. Feel free to calculate it yourself using this calculator or by adding the recipe to Yummly.