Preheat the oven to 350°F (175°C). Lightly coat two 8-by-5-inch loaf pans with cooking spray or a thin layer of oil, then place them aside.

In a medium mixing bowl, thoroughly whisk together the flour, cinnamon, baking soda, nutmeg, salt, cloves, and baking powder. Continue whisking until the spices and leavening agents are evenly dispersed throughout the flour.

Place the canola oil, granulated sugar, pumpkin purée, and room-temperature eggs in a large bowl. Whisk by hand or blend with a handheld mixer until the mixture is smooth and uniformly combined.

Gradually add the prepared dry mixture to the pumpkin mixture. Stir gently only until no visible streaks of dry flour remain. Scrape along the sides and bottom of the bowl with a flexible spatula to incorporate any unmixed ingredients without overworking the batter.

Divide the finished batter evenly between the two prepared loaf pans. Smooth the surface of each portion with a rubber spatula.

Transfer the pans to the preheated oven and bake for 45–55 minutes. Test the loaves by inserting a toothpick into the center; they are fully baked when it emerges clean.

Set the baked loaves, still in their pans, on a wire cooling rack for at least 10 minutes. Carefully remove them from the pans and allow them to continue cooling before applying the glaze.

While the bread cools, combine the confectioners’ sugar, milk or water, and vanilla extract in a small bowl. Whisk until the glaze becomes smooth and thin enough to drizzle.

Once the pumpkin loaves have cooled, spoon or drizzle the vanilla glaze evenly over their surfaces. Let the coating rest for several minutes so it can set before slicing and serving.