Preheat oven to 275°. Melt butter in a medium saucepan over medium heat and cook, stirring often, until butter foams, then browns (do not let burn), 5–8 minutes. Transfer to a bowl and whisk in brown sugar, honey, and vanilla. Set aside.
Pulse pecans in a food processor until almost a powder (you should have only a few larger pieces remaining). Combine pecans, oats, pumpkin seeds, coconut, orange zest, cinnamon, and salt in a large bowl; drizzle in reserved butter mixture and toss to combine.
Spread out granola on a parchment-lined rimmed baking sheet and bake, tossing occasionally, until golden brown, 40–50 minutes (mixture will still look wet but will dry as it cools). Let granola cool on baking sheet, then break into clusters. Mix in cranberries.