Preheat oven to 200°F (93°C). Line a large baking sheet with parchment paper or a silicone baking mat. Set aside.

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; you want every piece coated very well.

Spread the pretzels onto the prepared baking sheet. If they don’t all fit in a single layer, use two lined baking sheets. Sprinkle with coarse or flaky sea salt, if using.

Bake for 50–60 minutes, stirring every 15 minutes. Remove from the oven and cool completely.

Store completely cooled pretzels in an airtight container at room temperature for up to 1–2 weeks. If they soften slightly, spread on a baking sheet and warm in a 300°F oven for a few minutes to re-crisp.