Preheat oven to 275 degrees F. Line a rimmed baking sheet with parchment paper or a silicone baking mat.

Crush the pretzels to about a quarter of their original size, either using your hands or putting them in a resealable bag and crushing them with a mallet or rolling pin.

Place the crushed pretzels in a large bowl and add the sugars, milk powder and malt powder and toss to combine (I just used my hands). Pour the melted butter over the pretzel mixture and, using a wooden spoon, stir the mixture until it is evenly moistened and begins to clump.

Spread the pretzel mixture into an even layer on the baking sheet and bake until they look lightly toasted and smell buttery, about 20 to 25 minutes. Remove from the oven and allow to cool completely. Break up any large clumps and store in an airtight container at room temperature for up to 1 week (or store in the refrigerator or freezer for up to 1 month).