Preheat your oven to 350°F (175°C). Grease a 9-inch round cake pan with butter or oil, then dust with flour.

In a small saucepan, bring 1/4 cup of water to a gentle boil. Add the dried butterfly pea flowers and steep for 5-10 minutes until the water turns blue. Strain and cool the liquid.

In a large mixing bowl, combine 2 cups of all-purpose flour, 1 tablespoon of baking powder, and a pinch of salt. Whisk together until mixed.

In a separate bowl, whisk together the cooled butterfly pea flower tea, 1 cup of coconut milk, 1/2 cup of vegetable oil, 1 cup of granulated sugar, 2 eggs, 1 teaspoon of vanilla extract, and the juice of half a lemon until smooth.

Fold the wet ingredients into the dry mixture using a rubber spatula until just combined; batter should be lumpy.

Pour the batter into the greased cake pan, smoothing the top evenly.

Bake for 25-30 minutes until a toothpick inserted comes out clean, and edges are slightly golden.

Let the cake cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.

Frost with cream cheese frosting or whipped cream, and add lemon zest or edible flowers for decoration.