1cup + 3 tbsp (265g)plum puree, skin and pits removed, see note before starting
2 3/4cups (443g)dark bittersweet chocolate chips, 60% cocoa, see note before starting
Instructions
Spray the interior of a 7-inch springform pan with cooking oil spray. Line the bottom with a parchment round. Also line the sides with long strips of cut parchment paper.
Add plum flesh to a high powered blender and blend on high until you have a smooth puree. This can take a few minutes of blending on high speed. Measure out 265 grams of puree (about 1 cup + 3 tbsp) for the recipe.
Add chocolate chips to a microwave safe bowl. Microwave in 30-second intervals, stirring in between with a spatula, until the chocolate is completely melted and smooth. Alternatively, you could do this over low heat in a double boiler on the stove.
Add the plum puree to the melted chocolate and whisk until fully combined and the batter is uniform in color. Make sure your plum puree is room temperature before adding. If it is cold, it will cause the chocolate to seize.
Pour the mixture into the prepared cake pan. Smooth the surface with a spatula.
Put in the fridge to set, around 4-6 hours or overnight. Once cake is set, carefully release it from the cake pan and peel off the parchment paper. If desired, you can decorate the cake with frosting or fresh fruit before serving. The frosting I used is in the recipe notes.
Cut the cake with a large sharp knife. I recommend small slices because the cake is very rich. Store uneaten cake in an airtight container in the fridge or freezer.
Notes
Plum note: You will need around 6 medium plums to yield 265 grams of plum puree. This recipe works best with very ripe plums because the skin will be easy to remove and the plums will be sweeter. If the skin of your plums are not easy to remove, you can do a quick blanch to make it easier to remove the skin. You do want to make sure the skin is removed because the skin is very tart. After blending the plums, measure out 265 grams or 1 cup + 3 tbsp for the recipe. If you have a scale, I do recommend measuring with a scale for more accuracy. Adding too much puree can cause the cake to not set.
Blanch method for removing skin: Use a small sharp knife and score an "x" in the plum skin at the bottom of each whole plum (cut only the skin and not the flesh). Then cover the plums in a pot of simmering water for about 15 seconds. Remove plums and immediately place them in an ice bath. The skin should then peel off very easily.
Dark chocolate note: Make sure to use dark chocolate chips (sometimes labeled bittersweet chocolate chips) that contain around 60% cocoa. Anything less than 60% may cause the cake to not set. It should be okay to be a little higher than 60% but your cake will not be as sweet and may set slightly firmer. If you need the cake to be dairy-free, make sure to choose dairy-free dark chocolate. Also make sure your dark chocolate chips contain lecithin. Chocolate without lecithin may seize and harden once you add in the puree.
The cake in the photos include an optional chocolate ganache frosting.
Optional ganache frosting:
1 cup dark chocolate chips
1/2 cup (4 fluid ounces) canned coconut milk or heavy cream (if you don't need the cake to be dairy-free)
Add chocolate chips to a medium bowl and set aside. Heat coconut milk or heavy cream in a small pot or pan over medium low heat. Heat until simmering. Pour hot coconut milk/heavy cream over chocolate chips. Let sit for 60 seconds then gently mix until chocolate is completely melted.
Frost over the surface of the cake. You do not need to use all the frosting.
Estimated nutrition does not include frosting. The servings assumes 12 slices of cake. While the photos in this post show the cake cut into very generous sized slices, this is a very rich cake, so I recommend small slices, around 12-14 per cake.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.