Make the cake.  Preheat oven to 350 degrees F/325 degrees F convection.  Oil two 8 or 9 inch round cake pans and line the bottom with parchment.

In a large bowl, whisk together coconut oil, olive oil, coconut sugar, maple sugar, and vanilla until lightened in color and texture and fully incorporated.  A hand or stand mixer may also be used.  Beat in the eggs one at a time until fully combined.

Add half the flour, followed by the milk, then the remaining flour, along with the baking soda and powder.  Stir in the blueberries until the batter is combined and lump free.

Divide batter equally between the two pans and bake about 20 minutes until golden brown and a toothpick inserted in the center comes out clean or with a few moist crumbs.  Cool completely in the pan.  Cakes may be made up to 1 day ahead of assembly.

Make the roasted berries.  Preheat oven to 325 degrees F.  Line a rimmed cookie sheet with parchment.  Spread the berries into an even layer.  Drizzle with syrup and vinegar, and stir gently to combine.  Bake about 50 minutes, stirring frequently, until syrupy and jammy.  Cool completely on the pan.  Pour into a bowl and refrigerate up to one week.

When ready to assemble, make the frosting.  In a high powered blender, place the syrup, lemon juice, and almond milk.  Place the drained cashews in the blender.  Blend on high, using a tamper if necessary until creamy and smooth.  Give the frosting a stir, add the vanilla, and blend one more time.

To assemble the cake, place on cake layer on a stand or serving plate.  Spread some frosting around the perimeter of the cake and fill the center with berries.  Use a lot, though you will have some leftover for just about any use – toast, oatmeal, salad.  Top with the other cake layer and heap the cake with frosting, covering the top and sides.  Garnish with fresh berries and edible flowers if desired.

Cake may be stored in the refrigerator for up to 3 days.