This cake was created by vegan cooking blogger Hannah Kaminsky. She said she invented this cake during a cold a difficult winter because lemons "embody edible sunshine." If you can't find Meyer lemons, substitute regular lemons.
Whisk together remaining 3 1/2 cups flour, ground flaxseeds, baking powder, baking soda, and salt; whisk to combine.
Whisk together soymilk, lemon zest, and lemon juice in bowl; let stand 5 minutes. Whisk in agave nectar and oil. Stir soymilk mixture into flour mixture. Pour batter into prepared pan, and bake 1 hour, or until toothpick inserted in center of cake comes out clean. Cool in pan, then unmold.
Blend all ingredients in blender 5 minutes; Strain through sieve, then drizzle over cake.