In a large saucepan, combine brown sugar, maple syrup, butter, and cream. Bring to a rolling boil and then reduce the heat and simmer on medium low heat for 2 minutes. Remove from heat.
This step is tempering the eggs so that they don't scramble in your caramel mixture. In a small bowl, beat the eggs together with a fork. Add a tablespoon at a time of the caramel mixture to the eggs and whisk to combine. Continue adding caramel and whisking until the eggs have completely combined with the caramel. Pour back into your saucepan.
Add vanilla and chopped pecans and stir to combine.
Pour the pecan filling onto your crust and spread evenly with a spatula. Bake for 30-35 minutes. You will know its done when the top isn't jiggly and a toothpick inserted in the middle comes out mostly clean. If the top is getting too brown as it bakes, loosely cover with aluminum foil. Remove from the oven, set on a wire rack, and allow to cool completely before cutting into squares.
Once the bars have cooled, lift the parchment or foil from the pan and place on a cutting board. Slice into 36 bars. Enjoy!