Heat oven to 325 degrees Fahrenheit. Grease a 9x5" loaf pan.
In a medium bowl, beat together 4 large eggs, 2 large egg yolks, 1 tsp vanilla extract, and 100 g creme fraiche with a whisk or fork.
In a large mixing bowl or bowl of a stand mixer, combine 226 g unsalted butter, 200 g all purpose flour, 1/2 tsp kosher salt, and 1 tsp baking powder. Beat with mixer on low speed until just starting to combine. Scrape down sides of bowl.
Add 150 g brown sugar, 150 g granulated sugar, and 70 g almond flour to the bowl. Beat for 3-4 minutes on medium speed, until mixture becomes fluffy.
Stream in half of the egg mixture into the mixer bowl. Beat on low speed until just incorporated. Scrape down sides of bowl. Add the remaining half and beat on low speed again until just incorporated.
Transfer batter to prepared loaf pan and bake at 325F for 60-70 minutes, or until a toothpick inserted in the center comes out with only a couple crumbs attached.
Allow cake to cool in the pan for at least 10 minutes before removing from pan and cooling completely.