Prepare the Oven and Pan: Preheat the oven to 355°F (180°C). Lightly grease a 9.5-inch Bundt pan with vegan butter or coconut oil, making sure to coat the grooves thoroughly. Dust the greased pan with flour to help the cake release easily after baking.
Combine the Wet Ingredients: In a medium bowl or measuring cup, whisk together the almond milk, blood orange juice, canola oil, and vanilla extract until evenly combined. Set the mixture aside.
Mix the Dry Ingredients: Sift the flour, baking powder, and baking soda into a large mixing bowl. Add the salt and sugar, then whisk until the dry ingredients are evenly distributed.
Make the Cake Batter: Pour the wet mixture into the dry ingredients. Add the optional orange or lemon zest, if using, and stir gently until everything is just combined. Avoid overmixing, as this can make the finished cake dense rather than light and tender.
Fill the Bundt Pan: Transfer the batter into the prepared pan and spread it evenly. Gently tap the pan against the work surface a few times to help release trapped air bubbles and level the batter.
Bake the Cake: Place the pan in the preheated oven and bake for approximately 50 minutes. Test the thickest part of the cake with a toothpick; it should come out clean when the cake is ready. If the surface becomes too brown before the center is baked, loosely cover the cake with parchment paper and continue baking as needed. Cool Before Removing: Let the cake rest in the pan for 10–15 minutes after baking. Carefully turn it out onto a cooling rack and allow it to cool completely before adding the glaze. The cake is delicate while warm, so avoid removing it too soon.
Prepare the Orange Glaze: Sift the powdered sugar into a small bowl. Add 2 tablespoons of blood orange juice and stir until a smooth glaze forms. Add more juice from the measured amount as needed to reach a pourable consistency. If the glaze becomes too thin, mix in a little more powdered sugar.
Glaze the Cake: Once the cake has cooled completely, pour the orange glaze over the top, allowing it to flow naturally over the Bundt shape. Let the glaze settle before slicing and serving.
Serve the Cake: Cut the glazed cake into 12 portions and enjoy as a dessert or alongside tea or coffee.