Preheat the oven to 375 F. Butter a 9×13″ pan, and line with parchment paper.
Combine 1 1/8 cup (2 1/4 sticks) of butter with 3/4 cup brown sugar in the bowl of a stand mixer fitted with a paddle attachment. Beat until light and fluffy. Add 1/2 tsp salt, then the flour one cup at a time. Mix until dough forms into large clumps.
Press the dough into the bottom of your prepared pan, fork-prick the crust, and chill for 20 minutes. When chilled, bake for 18-20 minutes. Cool completely before proceeding.
Reduce oven temperature to 325 F.
Place remaining butter, brown sugar, honey, granulated sugar, heavy cream, and salt in a medium saucepan over high heat. Stir together and bring to a boil.
Cook until the mixture thickens enough to coat the back of a spoon, about 1 minute. Remove from heat, and stir in pecans and vanilla.
Pour the pecan mixture over the cooled crust, and bake for 15-20 minutes, or until the filling is bubbling.
Let cool completely before cutting into small pieces for serving.
