Preheat oven to 350 degrees F.
In a large bowl using a hand mixer OR in the bowl of a stand mixer with the whisk attachment, add room temperature butter, brown sugar, and sugar. Beat together until sugar is dissolved and butter is fluffy and pale yellow. About 3-5 minutes.
Add sour cream and continue to mix together. Scrape down the sides of the bowl and continue to beat together. Then add eggs, vanilla extract, almond extract, and mix together for another minutes. Batter should be smooth.
In a separate bowl, add flour, baking powder, baking soda, and kosher salt. Whisk together and add to the dry ingredients. Fold together until just combined, then add ¼ cup almonds and continue to fold together.
Spray a springform pan with nonstick baking spray and add batter. Bake for 35-40 minutes, until a toothpick comes out clean.
While the cake is baking, make the whipped mascarpone frosting. In a large mixing bowl using a stand mixer OR a stand mixer with the whisk attachment, add room temperature mascarpone, powdered sugar, heavy cream, and vanilla beans OR vanilla extract. Mix on low and gradually increase speed to high and frosting begins to come together. Scrape down the sides of the bowl as needed.
Once cake has cooled completely, add frosting to the top of the cake and top with remaining ¼ cup of almonds. Slice and enjoy!