01 -
Grab a baking sheet and cover it with parchment. Turn your oven on to 165°C so it heats up.
02 -
Dump your crushed graham crackers, cinnamon, salt, and sugar in a bowl. Give it a good mix.
03 -
Pour the melted butter and vanilla (if you want) into the dry bowl. Stir till everything's pretty much coated.
04 -
Spread out the coated mixture all over the parchment-lined sheet. Stick it in for 8 to 12 minutes. Take it out as soon as it smells toasty and looks golden—watch close so it doesn't burn.
05 -
Let it cool until it feels crisp. After it's cooled, grab handfuls and crush gently into big uneven bits.
06 -
Throw leftover crumble in a sealed container. It'll stay good for 3 days on the counter, a week in the fridge, or 3 months in the freezer. Let it hang out at room temp before digging in again.