Preheat oven to 350F. Spray a bundt pan with baking spray with flour, or grease and flour the pan. Set aside.
In a small bowl, mix up the ground flaxseed and water and set aside to thicken.
In a large bowl, zest the two lemons. Add in the flour, sugar, baking powder, baking soda, salt, and vegan butter. Use a whisk and combine until butter has been incorporated and mixture looks sandy.
Meanwhile, in a separate bowl, mix together your flaxseed mixture with the lemon juice, nondairy milk, oil, yogurt, lemon extract, almond extract, and vanilla extract. Whisk together.
Pour the wet ingredients into the dry, and gently mix to combine. Finally, add in your ½ cup of pistachios.
Transfer cake batter to your prepared loaf pan, and bake in preheated oven for 40-45 minutes, until a toothpick inserted in the center comes out clean. If the top seems to be browning too quickly, cover the cake with a piece of foil as it finishes cooking.
When the cake is cooked through, let it cool to room temperature in the pan, then transfer to a serving plate or rack to finish cooling off.
While the cake cools, prepare the glaze. Add your milk and vanilla to a small bowl and add the powdered sugar, a spoonful at a time, until a thick glaze forms. Make it a bit thicker than you think you need - it will melt a bit when it hits the warm cake! Think Elmer's glue consistency. When ready to serve, drizzle the glaze on top of your cake. Sprinkle on additional pistachios. Slice up and enjoy!