
Preheat the oven to 350 degrees F. Mix the wet ingredients in a bowl until well combined.
Add the 1 1/4 cup flour and the rest of the dry ingredients and whisk well to make a smooth batter. Add rest of the flour 1 tbsp at a time to make a smooth flowy batter, but not overly watery or overly stiff. You might not need all of the flour if using whole grain flour.
Pour the batter into a lined or greased pan. Even it out using a spatula.
Bake for 25 to 30 minutes if using a square baking dish or brownie pan. If the dish is stoneware, add a few more mins to the baking time. If baking a Loaf: 40 to 50 minutes, Cupcakes: 20 to 25 minutes for cupcakes. Test with a toothpick from the center. It should come out clean. Cool in the pan for 10 mins, then remove and let it cool completely before frosting.
Whisk the ingredients under frosting until smooth. Add 1-2 tbsp powdered sugar for sweeter frosting. Adjust the tang with lemon zest if needed. Add a drop or so vanilla extract or almond extract for flavor (optional). Chill the frosting for 15 mins if too flowy.
Spread the frosting on the cake evenly. Slice and serve. Store refrigerated for upto 4 days. The lemon flavor gets stronger on storing