Line an 8x8-inch pan with foil and coat it with cooking spray. Measure out all of your ingredients and have them at hand.
Place white chocolate chips and cookie butter in a large microwave-safe bowl. Heat on 50% power for 45 seconds--and stay close, because white chocolate can burn fast in the microwave. Stir well, then continue heating on 50% power in 25 second increments, stirring between each bout, until melted and smooth.
(Yes, you could also do this in a saucepan over medium-low heat on the stovetop, but that wouldn't be quite as quick!)
Once the chocolate and cookie butter are blended with no lumps, immediately stir in the pumpkin puree, spice, and vanilla extract. Combine it as fast as you can. Pour the fudge batter into the prepared pan. If desired, sprinkle turbinado sugar and some more pumpkin spice over the top.
Place in fridge to set for several hours before cutting and serving--this makes a lot! Keep stored in a sealed container in fridge, with blocks of fudge between layers of wax paper or parchment. The fudge softens fast at room temperature.
OM NOM NOM!