Preheat the oven to 350˚F and liberally grease a 9 x 9-inch pan with oil.
Place the halved cherries, sugar and water into a heavy based pan. Bring the pan to a boil and then reduce to a simmer. Cook the cherries for about 5 to 10 minutes until they have started to soften a little but still hold their shape. Whisk the arrowroot powder with a little water and drizzle into the cherry pan. The mixture will thicken almost immediately. Turn off the heat and pour the cherry mixture into the greased pan, set aside while you make the cake batter.
In a large bowl stir together the milk and vinegar, set aside to allow the mixture to curdle.
In a medium sized bowl sift together the oat flour, spelt flours, baking soda and baking powder. Stir in the almond flour and salt. This is the dry mixture. Set this aside while you continue to make the wet mixture.
Add the sugars, vanilla extract, almond extract and oil to the milk mixture and mix well. Add the dry mixture to the wet and mix until just combined - do not over mix. Add the flaked almonds and mix again.
Spoon the batter over the cherry mixture and gently spread it out as evenly as possible. Bake the cake in the centre of the oven for 30 to 40 minutes, until a wooden skewer inserted in the centre comes out clean.
When ready, remove from the oven and allow to cool down in the pan for at least 20 minutes. Loosen the edges of the cake from the side of the pan with a palette knife and turn the cake upside-down onto a serving plate. Sprinkle with some more flaked almonds if desired.
Serve while the cake is still warm with a steaming cup of coffee for a mid-morning treat. Or jazz it up with some vanilla ice cream or whipped cream for a fantastic, comforting dessert.