Preheat the oven to 350°F. Grease the sides of a 9-inch springform pan with baking spray. Line the bottom of the pan with baking paper.
Heat a saucepan over medium heat and add the butter. The butter will melt, start to foam, and then turn brown. Once browned and smelling nutty, about 5-8 minutes, remove from the heat and set aside.
In a medium bowl, whisk the eggs, ricotta, vanilla, orange zest, and orange juice.
In a separate bowl, mix the flour, sugar, baking powder, and salt.
Mix the dry ingredients into the wet. Pour over the brown butter and mix well until combined.
Gently fold the raspberries into the batter.
Pour batter into a prepared springform pan. Top with extra berries, chopped pistachios, and orange slices. Sprinkle sanding sugar over the top of the cake, if desired.
Bake for 50-60 minutes or until a toothpick inserted in the center comes out clean.
Transfer the cake to a cooling rack and allow it to cool completely before unmolding, about 2 hours.