Start by cooking the bloody chocolate caramel sauce by adding 1 dl sugar with 1/2 tbsp of water in a pot. Bring to a boil over medium heat and let it cook until the sugar caramelizes. This takes 3-5 minutes. Do not stir the sugar while it cooks to avoid sugar crystals from forming.
Remove the caramelized sugar from the hot stove. Let it cool for a minute. Place back on the stove on low heat, add cream, cacao powder and red food coloring. Stir to combine well and make sure they're no cacao lumps left. When you have a smooth sauce remove from the stove and set to cool.
Meanwhile preheat the oven to 175 degrees Celcius.
Combine milk and apple cider vinegar in a small bowl. Let it rest for about 10 minutes.
Prepare grease or prepare 6-8 muffin tins.
Combine oat flour, cacao powder, cinnamon ,baking powder, baking soda and salt in a bowl. Set aside.
Add two eggs and granulated sugar to a big bowl. Whisk the eggs until they turn pale and become light and fluffy. This takes about 3-5 minutes.
Add apple sauce, quark/greek yogurt and buttermilk (milk + apple cider vinegar). Gently stir to combine just until incorporated.
Next add the dry ingredients little by little to the wet. Gently stir together just until combined.
Divide the batter between the muffin tins, fill them 4/5 way up. Bake in the oven for 12-16 minutes, or until an inserted toothpick comes out clean. Remove from the oven and let them cool completely.
While the muffin bakes prepare the frosting by adding cream cheese, greek yogurt, stevia vanilla drops, cacao powder (start with 3/4 dl) and icing sugar. Mix until you have a fluffy and smooth cream. Taste to check if more cacao powder or sweetener is needed. Add more as needed and whisk again. If the frosting is too thick/thin either add a few drops of water or to thicken more cacao powder or icing sugar. Place in the fridge to set.
When the cupcake have cooled make small wholes in the middle using a melon baller or small spoon. Fill the wholes with the bloody chocolate caramel sauce.
Add frosting on top using a piping bag. Decorate with edible eyes or any other decoration of choice. Store in the fridge.