Preheat the oven to 350˚F (176ºC). Grease and flour a mini muffin tin.
Attach Sifter Attachment to KitchenAid Stand Mixer (with Paddle Attachment), and press "Tare" to zero scale.
Add granulated sugar to ingredient hopper and weigh. Turn Stand Mixer to speed 4 and sift sugar into bowl.
While sugar is sifting in, add the butter, vanilla and honey and beat until pale and fluffy. Add the eggs one at a time, beating well after each addition.
In a separate bowl, mix together the milk and sour cream. Add this to the butter mixture and stir on stir speed until thoroughly combined.
Add the flour and baking powder to the ingredient hopper to weigh, pressing "Tare" between each ingredient. Give the ingredients in hopper a stir to mix together. Turn Stand Mixer to "stir" and sift the flour and baking powder into the bowl. While sifting, add lavender and stir until just combined. 1 minute tops.
Scrape the mixture into the prepared muffin tin and bake in the oven for 15-18 minutes or until a skewer inserted into the middle comes out clean. Carefully remove the cake from the tin and place on a wire rack to cool completely.
While the cake is cooling, make the pistachios. Stir together honey and pistachios, tossing to coat well. Spread pistachios in 1 layer in a shallow baking pan and sprinkle with sugar and salt. Bake in middle of oven 15 minutes, then stir and bake 5 minutes more.
Transfer while still warm to a sheet of parchment paper or foil and, working quickly, separate pecans with a fork. Cool completely (about 1 hour) and remove nuts from parchment, breaking up any large pieces.
Top cakes with a drizzle of honey and candied pistachios.