Gently heat the buttermilk until warm. Do not bring to a simmer. Pour over the chamomile bags, cover, and steep for 30 minutes. Prepare the cream for the glaze at the same time. Remove the bags and squeeze out any liquid.
Preheat the oven to 350 degrees. Grease and flour a mini-bundt mold or muffin mold. Mix the dry ingredients together. Cream the butter and the sugar until fluffy. Mix in the eggs, zest, juice, and vanilla. Add the dry ingredients in two stages, alternating with the buttermilk. Mix until just combined. Spoon 3 tablespoons of batter into each mold cup. Bake for 25 minutes, rotating after 15 minutes. Remove from the oven and cool for 5-10 minutes. Invert onto a cooling rack and cool completely.
Place the cooling rack on a sheet pan and pour the warm glaze over the cakes. With a peeler shave the white chocolate. Sprinkle the curls over the cakes and garnish with lemon zest.