Start with the custard for the diplomat cream. Whisk egg yolks, sugar and butter on low heat until it thickens. Pour into a heat safe container, cover with lid and set aside.
For the cake, beat the egg yolks and sugar in a stand mixer. Heat the honey until it begins to bubble. Remove it, add the baking soda, and whisk continuously while it’s bubbling.
Slowly pour in the honey followed by the oil in the mixer. Add the flour and mix. Cover the bowl with plastic wrap and refrigerate for at least 4 hours .
For the cream, dissolve the gelatin in water. With an electric mixer, mix the powdered sugar and a bit of heavy cream. Slowly pour the remaining cream and beat until soft peaks form.