STEP 3:
Zest 5 blood oranges. Place zest of 2 blood oranges in a large measuring cup with olive oil. Set aside the zest of 3 blood oranges for the buttercream.
STEP 5:
Whisk flour, sugar, cocoa powder, salt & baking soda. Fold in olive oil mixture & water to the dry ingredients. Pour batter in four 6 inch cake pans & bake on 350F for 20 min.
STEP 6:
Beat butter with remaining blood orange zest until it's pale and fluffy. Add half the powdered sugar & beat until incorporated, then add second half of powdered sugar.
STEP 7:
Beat until the sugar is dissolved and buttercream feels smooth. Slowly pour in vanilla & blood orange juice. Beat until everything is fully combined.
STEP 8:
Bring half and half to a simmer., remove it from the heat & pour it over the chocolate & let it sit for one minute. Stir the chocolate until it is completely smooth.
STEP 10:
Refrigerate for at least 30 min & then pour chocolate ganache on top. Refrigerate for another 15 min & then top with the candied orange slices.