Preheat the oven to 350°F (175°C). Grease a 9x5-inch loaf pan and line it with parchment paper.

In a small bowl, mix the ground flaxseed and water. Let it sit for 5 minutes until thick and gel-like.

In a large bowl, whisk together the pumpkin puree, brown sugar, oil, oat milk, vanilla extract, apple cider vinegar, and flax mixture until smooth.

Add the flour, baking soda, baking powder, salt, cinnamon, nutmeg, cloves, and pumpkin pie spice. Stir gently until no dry flour remains.

Fold in the pepitas or any optional add-ins. The batter should be thick but easy to spread.

Pour the batter into the prepared loaf pan and smooth the top with a spatula.

Bake for 55–65 minutes until the top is golden brown and your kitchen smells warm and spicy.

Insert a toothpick into the center. It should come out with a few moist crumbs but no wet batter.

Cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.

Slice and serve once fully cooled for the best texture and clean slices.