In a medium bowl, whisk the milk, pumpkin pie spice, pudding mix and pumpkin puree until the pudding thickens, 2 minutes. Set aside.
Place the brioche in a shallow bowl. Pour the liqueur over and let soak for 2 to 3 minutes.
In a small bowl, mix the sour cream, honey and cinnamon until well blended.
In a trifle dish, layer half of the brioche, then half of the pudding, then the remaining brioche and the remaining pudding so that there are 2 layers of each. Top with a dollop of the sour cream mixture and sprinkle with the butterscotch chips.