Preheat the oven to 375ºF. Generously coat two 12-cup mini muffin tins cooking spray.
Add butter to a small pot over medium-low heat. Cook until the butter is melted, turns a deep golden color, and little browned bits begin to appear, 7 to 8 minutes. Whisk the honey and violet syrup into the pot, and set aside to cool slightly.
Add the egg whites to a deep bowl. Whisk until foamy, 30 to 60 seconds. Stir in the flours, sugar, salt, and zest. The batter will be quite thick.
Fold in the butter mixture.
Evenly spoon the batter into the prepared tins. Gently push a raspberry into the top of each cake, just enough so it stick into the batter but doesn’t get buried inside it.
Bake until deeply golden around the edges, 11 to 12 minutes. Remove from the oven, and let sit in the pan on a wire rack for 10 minutes. Transfer cakes from the pan to the rack, and let cool completely. Dust with Confectioner’s sugar, if desired, before packaging.