Preheat oven to 350°F.
Line a baking sheet with aluminum foil and parchment paper.
Spread the oyster crackers out on the baking sheet.
Melt the butter in a saucepan.
Add the brown sugar, cinnamon, and vanilla to the melted butter. Bring to a rolling boil and cook for 2-3 minutes.
Pour the caramel mixture over the crackers and mix until fully coated.
Spread the coated crackers back out in a single layer on the baking sheet.
Bake for 7-9 minutes.
Crush the sea salt into smaller flakes and sprinkle over the baked crackers.
Let the crackers cool, then break them up into bite-sized pieces.
