First, gets your oven warming up to 350°F (175°C). While it heats, lightly grease a 9×5-inch loaf pan and line it with parchment paper so the cake lifts out easily later.
In a large mixing bowl, beat the vegan butter and sugar together until the mixture looks pale and fluffy. Take your time with this step—it helps give the cake a soft, tender texture.
Next, add the dairy-free yogurt, oat milk, vanilla extract, and almond extract. Mix everything together until the batter looks smooth and creamy.
In a separate bowl, sift together the flour, cornstarch, baking powder, and salt. Slowly add the dry ingredients into the wet mixture, folding gently as you go. Stir just until everything is combined. Be careful not to over mix, as that can make the cake dense.
Pour the batter into your prepared loaf pan and smooth out the top. Place it in the oven and bake for 60 to 70 minutes. The cake is ready when a toothpick inserted into the center comes out clean. If you notice the top browning too quickly, loosely place a piece of foil over it during the last 15 minutes of baking.
Once baked, let the cake cool in the pan for about 15 minutes. Then carefully transfer it to a wire rack and allow it to cool completely.
To make the glaze, whisk together powdered sugar, non-dairy milk, vanilla bean seeds, and vanilla extract until smooth. Drizzle the glaze over the fully cooled cake and let it set before slicing and serving.