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.
03 - Beat softened butter and granulated sugar in a large bowl until light and fluffy, approximately 3-4 minutes. Add eggs one at a time, mixing well after each addition. Blend in chopped lavender and vanilla extract.
04 - Alternately add 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, smoothing the top evenly. Bake for 25-30 minutes or until a wooden toothpick inserted into the center comes out clean.
06 - While cake bakes, combine water, sugar, and lavender buds in a small saucepan. Simmer for 3 minutes, then strain through a fine-mesh sieve. 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 with a skewer and gently brush with warm lavender syrup. Cool completely before glazing.
08 - Whisk powdered sugar, lemon juice, and chopped lavender until smooth and pourable. Drizzle evenly over the completely cooled cake. Allow glaze to set for 15-20 minutes before slicing.