Melt 6 tbsp of the butter in a small pan. Add 3 bay leaves, cover and let steep for about an hour. Remove the bay leaves and toss them. Preheat the oven to 350 degrees F.
Use the outside bottom of the pan to trace and cut out a piece of parchment paper for the bottom liner for the pan. Prepare a loaf pan using butter or shortening and dust with flour, then place the cut piece of parchment paper in the bottom of the pan.
Dot one side of the remaining bay leaves with a dab of butter and lay them out in the bottom of the pan, butter side down on the parchment paper.
In a large bowl whisk the flour, sugar, baking powder and salt together. In a medium bowl combine the eggs, sour cream or greek yogurt, and melted butter; gently stir the wet mixture into the flour mixture just until the batter is smooth, do not over mix.
Scrape batter into the pan carefully covering the bay leaves. Put the remaining butter in a plastic baggie, close and snip off a small tip of the corner. Squeeze the butter in a line down the center of the batter; bake for 45-50 minutes or until a cake tester inserted in the middle comes out clean.
Remove from the oven and cool for 10 minutes, loosen the cake from the sides of the pan with a thin knife. Turn onto a rack to cool completely. Peel off the parchment paper and bay leaves. Dust the top with powdered sugar.
Slice and serve when cool, top with your favorite fruit or preserves.
