Preheat oven to 350℉ and heavily grease a 10-12 cup bundt pan. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment beat together butter and sugar on medium speed until light and fluffy, scraping down the sides halfway through.
Add eggs one at a time until incorporated, scraping down the sides as needed.
Add vanilla bean paste and mix.
In a separate, medium bowl, whisk together flour, baking powder, baking soda, salt, nutmeg, and cardamom.
Gradually add flour mixture, sour cream, and buttermilk to butter mixture on low speed, alternating between each ingredient. Mix until just combined. Some slight flour should remain.
Remove bowl from mixer and use a spatula to scrape down sides and bottom of bowl to fold in any pockets of flour.
Transfer batter to prepared bundt pan. Tap pan firmly several times to release any air bubbles.
Bake for 45-50 minutes or until toothpick inserted into the center comes out clean.
Remove cake form oven & allow to cool for ten minutes. After ten minutes, invert the cake out of the pan onto a cake platter to release from the pan. Allow to cool.