01 - Line a 9x9-inch baking pan with parchment paper, allowing some overhang for easy removal.
02 - In a medium saucepan over medium heat, combine granulated sugar, brown sugar, unsalted butter, evaporated milk, pumpkin puree, espresso powder, cinnamon, nutmeg, and salt. Stir continuously until the mixture reaches a steady boil.
03 - Continue boiling the mixture, stirring often, for 8 to 10 minutes or until it reaches 234°F on a candy thermometer.
04 - Remove saucepan from heat. Immediately add white chocolate chips and marshmallow crème. Stir vigorously until fully melted and the mixture is silky smooth.
05 - Stir in vanilla extract until evenly combined. Pour fudge base into prepared pan and level the surface.
06 - In a small skillet set over medium heat, melt the unsalted butter. Add pecan halves, granulated sugar, and a pinch of salt. Cook, stirring often, until sugar is dissolved and pecans are caramelized and toasted, about 3–4 minutes.
07 - Evenly distribute praline topping over fudge, pressing gently to adhere.
08 - Allow fudge to cool at room temperature for 30 minutes, then refrigerate for at least 1 hour until completely set.
09 - Using the parchment paper, lift fudge from the pan. Cut into squares and serve.