Place the butter in a sauce pan and heat it over medium/high heat until it begins to melt and foam. Continue to cook for another minute or so, until the butter becomes amber brown and develops a nutty aroma.
Transfer to a large heatproof bowl and allow to cool in the fridge until solid, for about 30 minutes, or you can freeze the butter for 15 minutes, or until it becomes solid. Once solid, remove from fridge and set aside to bring back to room temperature.
Preheat oven to 350° F. Line a 9" springform pan with parchment paper and grease the sides.
Beat browned butter until it becomes creamy, then add in the sugars and one teaspoon of the vanilla. Beat for 2-3 minutes, until well combined and creamed. Beat in the eggs, one at a time, fully incorporating each before adding the next.
In another mixing bowl, combine the flours, salt and baking powder. Add the dry ingredients to the wet mixture and mix just until combined.
Spoon batter into the prepared pan and bake on the center rack for 35-40 minutes, or until a tester inserted into the center comes out clean.
let cake cool completely, then remove from pan.
Place the cream, honey, and 1 teaspoon vanilla in a mixing bowl and beat with an electric mixer until stiff peaks form. Spread the cream over the top of the cooled cake. Top with berries and serve!
Recipe by The Kitchen McCabe at https://www.thekitchenmccabe.com/2017/09/24/browned-butter-buckwheat-cake-vanilla-cream-berries/