Preheat the oven to 350°F.

Pick the lilac blossoms from the stem and discard the leaves and stems. Combine the sugar and lilac blossoms in a food processor and pulse until the petals are mostly broken down.

In a bowl, combine flour, baking powder, baking soda, and salt and whisk together.

In a small measuring cup, combine milk and lemon juice, whisking together.

In a stand mixer, beat together the softened butter and lilac sugar until creamy. Scrape down the sides as needed.

Add eggs one at a time, ensuring each is fully incorporated before adding the next.

Gradually add flour mixture and soured milk alternately, starting with flour and ending with flour. Mix until just combined.

Spray a mini Bundt cake mold with non-stick spray and fill each cavity with batter, ensuring it's level.

Bake for 20 to 25 minutes or until a toothpick comes out clean.

While cakes are baking, combine sugar and water in a saucepan and bring to a simmer to dissolve.

Remove from heat, add lilac blossoms, cover, and steep until cakes are done baking. Strain and set aside syrup.

In a bowl, whisk together reserved syrup, icing sugar, and milk for the glaze, adjusting consistency as needed.

When cakes are baked, brush tops with syrup, cool briefly, and unmold onto parchment.

Once cool, brush again with syrup and drizzle with glaze.

Allow the glaze to set before serving.