01 - Preheat the oven to 350°F. Grease and flour an 8-inch round cake pan thoroughly.
02 - Whisk together flour, baking powder, and salt in a medium bowl. Set aside for later use.
03 - In a large bowl, cream softened butter and granulated sugar until mixture appears light and fluffy, approximately 3-4 minutes. Beat in eggs one at a time, fully incorporating each before adding the next. Blend in chopped lavender and vanilla extract.
04 - Alternate adding the flour mixture and milk to the butter mixture, beginning and ending with the dry ingredients. Mix until just combined, being careful not to overmix.
05 - Pour batter into the prepared pan and smooth the top evenly. Bake for 25-30 minutes or until a toothpick inserted in the center emerges clean.
06 - While cake bakes, combine water, sugar, and lavender in a small saucepan. Simmer for 3 minutes, then strain and set aside to cool slightly.
07 - Allow cake to cool in the pan for 10 minutes. If using syrup, poke small holes across the surface and lightly brush with warm syrup. Let cake cool completely before removing from pan.
08 - Combine powdered sugar, lemon juice, and finely chopped lavender in a small bowl. Whisk until completely smooth and free of lumps.
09 - Drizzle the glaze evenly over the completely cooled cake. Allow glaze to set for 15-20 minutes before slicing and serving.