2 1/2 c. heavy whipping cream
1 (10 oz.) bag peanut butter chips (save some to garnish)
18 graham crackers

Heat 2/3 cup cream in a large microwave safe bowl until steaming. Add chips; whisk until smooth. Slowly whisk in remaining cream. Chill in refrigerator for 15 minutes.

Beat with mixer just until soft peak forms. Arrange 3 crackers side by side, long edges touching on serving plate. Spread evenly with 1/2 cup cream mixture. Repeat 4 more layers. Add one more layer of crackers and chill one hour. Chill remaining cream. Spread top and sides of cake with cream mixture. Chill 4 hours. Garnish with peanut butter chips.