Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
In a large mixing bowl, cream the softened butter and granulated sugar together until light and fluffy, about 3-4 minutes.
Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
Gradually add the dry ingredients to the butter mixture, alternating with the buttermilk. Begin and end with the dry ingredients. Mix until just combined.
Gently fold in the raspberries and shredded coconut.
Divide the batter evenly between the prepared cake pans. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cakes to cool in the pans for 10 minutes, then transfer to wire racks to cool completely.
While the cakes are cooling, prepare the frosting. In a large bowl, beat the softened butter until creamy. Gradually add the powdered sugar, mixing until smooth. Add the heavy cream and vanilla extract, and beat until fluffy.
Once the cakes are completely cool, place one layer on a serving plate. Spread a layer of frosting on top, then place the second layer on top. Frost the top and sides of the cake.
Press the remaining shredded coconut onto the sides and top of the frosted cake.
Serve immediately or refrigerate for up to 3 days.