To make the cake:
Grease an 8-inch springform cake pan with butter and line with parchment.
Preheat oven to 350 degrees F.
In a saucepan heat the cranberries and 3/4 cup sugar over medium heat, just until the cranberries start to burst and sugar melts.
Turn off the heat and stir in the raspberries.
Pour the berries into the prepared pan.
Mix the batter:
Cream together the butter, 1 1/4 cups sugar, zest and vanilla until light and fluffy, 5 to 8 minutes. Scrape down the bowl and add the eggs, one at a time, scraping after each. In a separate bowl whisk together the flour, baking powder, baking soda and almond meal. Add half the dry ingredients to the butter mixture, mix to incorporate, then add half the buttermilk. Repeat with the remaining flour and buttermilk. Mix just until it is smooth.
Spread the batter evenly over the berries.
Place the pan on a baking sheet covered with foil, just in case the berry juices leak from the pan. Bake for about 1 hour 15 minutes, or until a tester comes out clean. Let the cake cool for about 30 minutes.
Invert the cake onto a platter.