Preheat your oven to 350F/180 C and line a springform pan with parchment paper. Thinly slice the lemon and orange into thin rounds. Arrange the slices on the bottom of the prepared springform pan. Set the pan aside.
To a bowl, add the almond flour, coconut flour, baking powder, and salt. Whisk to combine. Set the bowl aside.
To another bowl, add the softened butter, erythritol, and vanilla extract. Using a hand mixer, whisk until combined. Add 2 eggs and beat until light and fluffy.
Add the ricotta cheese, lemon juice, orange zest, and lemon zest. Beat until combined. Add half of the dry mixture, beat, then add the remaining 2 eggs and beat again.
Add the remaining dry mix and beat until just combined. Pour the cake batter over the citrus slices in the prepared springform pan. Transfer the pan to the preheated oven.
Bake the cake for 45-50 minutes until an inserted toothpick comes out dry. Let it cool for 15 minutes. Remove the cake from the pan and flip it on a serving plate. Peel off the parchment paper to reveal the citrus slices.
Cut the cake into 8 slices. Garnish with some micro mint leaves and serve.