Step 1: Preheat your oven to 250°F (120°C). Line a large rimmed baking sheet with parchment paper or a silicone baking mat for easy cleanup.
Step 2: In a small bowl, whisk together the vegetable oil, garlic powder, onion powder, cayenne pepper, and lemon pepper until the spices are well-distributed throughout the oil.
Step 3: Place the pretzels in a very large mixing bowl. Pour the oil and spice mixture over the pretzels.
Step 4: Using a large spatula or your hands, toss the pretzels thoroughly until every piece is evenly coated. Let the pretzels sit for 10 minutes, tossing once or twice to allow the oil to soak in.
Step 5: Spread the pretzels out in an even, single layer on the prepared baking sheet.
Step 6: Bake for 45 to 60 minutes, removing the tray to stir the pretzels every 15 minutes to ensure even roasting and to prevent burning.
Step 7: Remove from the oven when the pretzels appear dry and slightly toasted. Allow them to cool completely on the baking sheet before serving or storing.