Preheat the oven to 350°F. Line a cookie sheet or jelly roll pan with parchment paper or aluminum foil leaving enough overhang to easily lift from the pan. If using foil, generously butter.
Lay the graham crackers side by side without overlapping.
On the stovetop in a heavy bottomed saucepan, melt together the butter, light brown sugar and 1/4 tsp sea salt. Once melted, bring to a boil and cook for 2 minutes stirring constantly over medium heat.
Remove from the heat and add the ground cinnamon, vanilla and pecan pieces. Stir until combined.
Pour the hot mixture over the graham crackers spreading until all are covered. Sprinkle the top with 1/4 cup toffee bits.
Bake for 10 minutes until bubbly. Remove from the oven and sprinkle with the remaining sea salt.
Place onto a cooling rack to cool completely, then chill.
Use a sharp knife to cut into desired shapes.
Store at room temperature tightly sealed for up to one week.