Soak cereal in heavy whipping cream for at least 30 minutes or up to overnight. Once soaked, take a strainer and place it over a medium sized bowl to strain out your heavy whipping cream from the cereal and discard the soaked cereal. Be sure to use a spatula and press the cereal down to get ALL of the liquid out! You should end up with TWO CUPS of heavy whipping cream (If you don’t soak your cereal overnight you may have a bit more than 2 cups; we will only be using 2 cups for this recipe)
While your cereal and heavy whipping cream are soaking you can go ahead and prepare the cereal that will be mixed into the ice cream base. Take your 3 cups of cereal and place it in a large pan with 1/4 cup of sugar and 1 tbsp butter. Bring to medium heat and heat this until the sugar and butter melt. Be sure to continually toss it as you heat it and get it all mixed in there and evenly coated! Once evenly coated with melted butter & sugar remove from heat and allow to cool fully! (this will take only a few minutes, 3-5!) Once fully cooled reserve a few full pieces to add on top then you’ll use your hands to crush the cereal into smaller pieces
Note: if you cook this too long it will burn. You just want everything to melt and then toss to coat! You’ll begin to smell burnt sugar if you cook it too long, just remove from heat immediately and continue to stir if this happens.
Now you can prepare your cinnamon swirl. Simply combine the cinnamon swirl ingredients (melted butter, brown sugar and cinnamon) to a bowl. Allow this to cool fully!
To prepare the ice cream base pour your 2 cups of cereal soaked heavy whipping cream into a large bowl or stand mixer. Begin to mix on low then slowly increase speed. Mix for ~3 minutes until stiff peaks form and you’ve made whipped cream!
In a separate large bowl combine sweetened condensed milk, vanilla extract and cinnamon. Mix it well.
Gently fold in your whipped cream to the sweetened condensed milk mixture. Do not stir this vigorously! You don’t want to reduce the air in the whipped cream. Mix this for ~2-3 minutes until totally uniform and no lumps of whipped cream are present.
Reserve ½ cup of the crushed cinnamon toast crunch (put this with the full pieces- this will be your topping!) and add the rest of your crushed cinnamon toast crunch pieces to the ice cream base and fold it in.
Now it’s time to assemble the ice cream! Add ⅓ of the ice cream base to the container (a baking loaf pan works great!) then place ⅓ of the cinnamon swirl on top in a few dollops and use a knife to swirl it. Repeat with remaining ⅔ (you’ll end on the cinnamon swirl!)
Top with the remaining crushed cereal as well as the whole pieces that you reserved
You want to have a good amount on top so that you can tell “Oh! This is cinnamon toast crunch cereal ice cream!” but not enough so you can’t SEE any of the ice cream base! Be sure there are some reserved whole pieces so that yo you can clearly tell it’s cinnamon toast crunch cereal!
Freeze for 6-8 hours and enjoy!