Add the pudding mix, water, pumpkin puree, sweetened condensed milk, and pumpkin pie spice to a large bowl. Use a whisk to mix until smooth. Make sure there are no lumps! Cover and transfer to the fridge to chill for at least 4 hours, or overnight until it sets up.
Once the pudding has set up, whip the heavy cream until soft peaks form. Add 1/3 of the whipped cream into the pudding mixture. Use a rubber spatula to lightly fold the whipped cream in. Add the remaining whipped cream and mix until combined.
Add the cookie butter to a bowl and microwave for 20-40 seconds, until melted and smooth.
In a trifle bowl, add a layer of pudding. Top with biscoff cookies, then add another layer of pudding, then drizzle on plenty of cookie butter. Continue to layer until you use all the pudding mixture!
Refrigerate for at least another 30 minutes before serving. Enjoy!