Line an 8 x 8" pan with parchment paper.

Place white chocolate and peanut butter in a large microwave safe bowl. Heat on 50% power for 1 minute. Stir then continue heating at 50% for 30 second increments, stirring between each, until melted and smooth.

Remove from heat and immediately stir in the pumpkin puree, spice and vanilla.

Pour into the prepared pan and let cool to room temperature on the counter. Chill until set in the refrigerator and cut into squares.