Step 1: Preheat your oven to 275°F (135°C). Line a large baking sheet with parchment paper.
Step 2: Wash the kale thoroughly. Remove the tough stems from the kale leaves and tear the leaves into bite-sized pieces (approx. 1-2 inches).
Step 3: Dry the kale completely. Use a salad spinner, then spread the pieces on clean kitchen towels and pat dry. Let air dry for 15-20 minutes to ensure all moisture is gone.
Step 4: In a large bowl, drizzle the dried kale with olive oil. Use your hands to gently massage the oil into every piece of kale until lightly coated.
Step 5: Sprinkle the nutritional yeast, garlic powder, and sea salt (and any optional spices) over the kale. Massage again to distribute the seasonings evenly.
Step 6: Arrange the seasoned kale in a single layer on the prepared baking sheet. Do not overcrowd; use two sheets if necessary to prevent steaming.
Step 7: Bake for 15-25 minutes, or until the kale is crispy and slightly browned. Check frequently after 15 minutes to prevent burning.
Step 8: Halfway through baking (around 10-12 minutes), gently flip the kale pieces or toss them to ensure even crisping.
Step 9: Remove from oven and let the kale chips cool completely on the baking sheet. They will become even crispier as they cool. Store in an airtight container for up to 3-4 days.