Step 1

Preheat your oven to 350°F (180°C). Grease a 9x5 inch (22x13 cm) loaf pan or line it with parchment paper.

Step 2

In a medium bowl, whisk together flour, cornstarch, baking powder, baking soda, and salt. Set aside.

Step 3

In a large bowl, mix the sugar with lemon zest to combine.

Step 4

Add the eggs and softened butter and beat until creamy and well combined.

Step 5

Add in the sour cream, vanilla extract, lemon extract, and lemon juice. Mix until well combined.

Step 6

Slowly add the dry ingredients to the wet ingredients and mix until well incorporated. Be careful not to overmix.

Step 7

Add the food coloring (if using), and mix well.

Step 8

Pour the batter into the prepared loaf pan and smooth the top with a spatula.

Step 9

Bake for about 45-50 minutes, or until a toothpick inserted in the center of the cake comes out clean.

Step 10

Allow the loaf to cool in the pan for about 10 minutes before removing it to a wire rack to cool completely.

Step 11

While the loaf is cooling, prepare the icing: In a small bowl, whisk together the powdered sugar, and 2 tablespoons lemon juice. If the icing is too thick, add more lemon juice (a little at a time) until you get the desired consistency. It should be thick but pourable.

Step 12

Once the loaf is cooled, drizzle the icing over the top. You can use a spoon or a piping bag with the corner snipped off. Let the icing set for a bit before slicing and serving.