Slice the tempeh in half widthwise (so you have 2 even squares), then thinly slice each square in thirds so you have six very thin squares (it’s easiest to do this by placing the tempeh flat on your cutting board and holding the knife horizontally for an even cut). Then slice each square into three rectangular strips. You should have ~18 pieces of tempeh (as the original recipe is written).
In a shallow bowl, rimmed plate, or baking dish, whisk together the oil, tamari, maple syrup, salt, liquid smoke, smoked paprika, black pepper, and cayenne (optional). Taste and adjust flavor as needed. It should be quite salty, smoky, a little spicy, and plenty sweet (even a little too sweet, as it needs to balance the bitterness of the tempeh).
Add the tempeh and toss to coat (using a pastry brush is helpful for fully coating). Marinate for 10-15 minutes, flipping once for even flavor dispersion.
Preheat the oven to 400°F (204°C) and line a baking sheet with parchment paper.
Transfer tempeh (reserving excess marinade for brushing) to the parchment-lined baking sheet and arrange in a single layer.
Bake for 10 minutes, then remove from the oven, flip, and brush generously with reserved marinade. Bake for 8-10 minutes more, or until browned and slightly crispy.
Enjoy immediately or store cooled leftovers in an airtight container in the refrigerator for 5 days, or in the freezer for up to 2 months. Reheat in a 350°F (176°C) oven or on the stovetop over medium heat until hot.
*Nutrition information is a rough estimate calculated with avocado oil and without optional ingredients.