1. Grease 4 of the molds of a mini bundt pan. Preheat oven to 350 degrees F.
2. In a small bowl, whisk together *cake flour, AP flour, baking powder and salt. Set aside.
3. In a small saucepan heat butter and milk over low heat until the butter has melted down completely. Add the vanilla extract and set aside.
4. In the bowl of your stand mixer with the whisk attachment, whip the egg whites until foamy. Add the sugar and cream of tarter then whip again until stiff peaks form.
5. Add the flour mixture to the meringue and whisk on low speed until everything is incorporated.
6. Finally, fold in the melted butter, until smooth. Pour the batter into the prepared bundt pan and bake until lightly golden or until the cake tester comes out clean; about 12 minutes.
7. Let the bundts cool in the pan while you prepare the cream filling.

For the Cream filling: combine all the ingredients in the bowl of your stand mixer and beat until light and fluffy.

1. Once the bundts have cooled completely, poke little holes all around the bundts.
2. Transfer the cream into a piping bag and fill each hole made in the bundts with the cream. If the cream oozes out, simply scrape the excess with a knife.
3. Carefully transfer the bundts to a serving plate and dust with powdered sugar before serving.