Preheat oven to 200°F (93°C). Line a large baking sheet with parchment paper or a silicone baking mat.
In a small bowl or liquid measuring cup, whisk together the oil, honey, brown sugar, Dijon, ground mustard, onion powder, and salt until emulsified.
Break the pretzels into pieces. Place them in a large zipped-top bag or in a large bowl. Pour the honey mustard mixture over the pretzels. Shake or stir thoroughly.
Spread the pretzels onto the prepared baking sheet. If they don't all fit in a single layer, use two lined baking sheets.
Bake for 50–60 minutes, stirring every 15 minutes.
Remove from the oven and cool completely.
