Grease a large bundt tin (or cake tin) and set aside.
Measure the flour, sugar, cocoa powder, baking powder, bi-carb soda and salt into the Thermomix bowl and sift on Speed 8, 5 seconds. Set aside in a separate bowl.
Place the the buttermilk, oil, room temperature eggs and vanilla in the Thermomix bowl and mix on Speed 3 until well combined.
With the blades on Speed 2, slowly add the dry ingredients to the wet ingredients and mix until combined.
Pour in the coffee and mix on Speed 2 until combined.
Pour the batter into the prepared tin and bake for approximately 35 minutes or until a toothpick inserted in the center comes out clean (don't overcook the cake - you want it to be nice and fudge-like!).
Allow to cool completely.
To make the frosting add the icing sugar to the Thermomix bowl and mix on Speed 9, 10 seconds then add all of the remaining ingredients and mix on Speed 4, 30 seconds or until light and fluffy.
Spread the frosting over the cake and decorate with fresh raspberries (optional).
Store in an airtight container at room temperature for 3-4 days.
Please note that keeping the cake at room temperature will result in a beautiful, moist texture.