Line 8 x 8 baking pan with parchment paper and butter thoroughly.
In a 3-quart heavy-bottomed saucepan combine butter, maple syrup, cream, sugar, corn syrup and salt. Stirring constantly, cook over low heat until sugar has dissolved (about 10 minutes). Clip candy thermometer to the pan. Bring mixture to a boil over medium heat and cook, without stirring, until mixture reaches 240 degrees on candy thermometer (about 20-25 minutes). *Do NOT stir, as sugar will crystallize!
Remove pan from heat and let mixture cool until candy thermometer drops to 160 degrees.
Pour mixture into mixing bowl.
Add vanilla extract to mixture and beat until mixture loses glossy appearance (about 5-10 minutes).
Fold in pecans and mix thoroughly.
Transfer mixture to parchment lined pan. Press fudge evenly into pan. Place pan on a cooling rack and score fudge into desired sized bites. Cool thoroughly (about 2 hours).
Flip over onto a cutting board, remove and discard parchment. Flip again so score marks are visible.
Using a sharp, heavy knife, cut fudge.
Place fudge in waxed paper lined air-tight container. Place waxed paper in between each layer of fudge.