Preheat Oven: Set your oven to 350°F (175°C).
Prepare Pan: Grease and flour an 8-inch round cake pan or line it with parchment paper.
Mix Dry Ingredients: In a large bowl, whisk together the flour, sugar, matcha powder, baking powder, baking soda, and salt.
Combine Wet Ingredients: In a separate bowl, mix the almond milk, vegetable oil, apple cider vinegar, and vanilla extract until well combined.
Combine Wet and Dry Mixtures: Pour the wet ingredients into the dry ingredients and stir until just combined, being careful not to overmix.
Pour into Pan: Transfer the batter into the prepared cake pan, smoothing the top.
Bake: Place the pan in the preheated oven and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
Cool: Remove from the oven and let the cake cool in the pan for about 10 minutes. Then, transfer it to a wire rack to cool completely before frosting or serving.