Preheat oven to 350 degrees F and line a baking sheet with parchment paper.
In a large bowl, melt the butter and then let cool for 5 minutes.
Once butter has cooled, add the egg white and vanilla then mix until smooth.
In a small bowl, mix together the cinnamon, sugar, and cardamom (if using). Set aside.
Add the pretzels to the large bowl and toss in the butter mixture until fully coated. Slowly sprinkle the sugar mixture over the pretzels and gently toss until completely coated.
Transfer the pretzels to the prepared baking sheet and spread into an even layer.
Bake for 16-18 minutes, stirring the pretzels half way through.
Let pretzels cool before breaking apart and serving.
