Preheat oven to 350 degrees F. Line a jelly roll pan (half sheet pan) with a Silpat baking mat. Or you can line it with parchment paper or wax paper.
Arrange 15 graham crackers sheets on the pan in a single layer, you'll have three rows of five. 15 sheets equals 30 squares of crackers.
In a small, nonstick saucepan over medium heat, melt together the stick of butter and brown sugar. Gently boil the mixture, without stirring, for 3 minutes.
Remove the pan from the heat and carefully add the vanilla, giving it a good stir with a rubber spatula.
Evenly pour the brown sugar mixture over the graham crackers. Use an offset spatula to spread it evenly to the edges of the crackers.
Evenly sprinkle the chopped pecans over top of the graham crackers. Bake at 350 degrees for 10 minutes.
Sprinkle the praline grahams evenly with the sea salt. Allow them to cool on the pan for about 10 minutes. Then break them apart into 30 squares.