For the rhubarb compote:

1. Combine all ingredients in a small saucepan and cook over medium-high heat for 8 to 10 minutes, until you have a loose jam-like consistency. Transfer the compote to a bowl or glass jar and cool completely.

For the meringue cake

1. Preheat oven to 350 F. Grease the inside of two 9-inch cake pans and line bottoms with parchment paper.
2. In a medium bowl, whisk together the egg yolks, 1/2 cup (100 g) sugar, yogurt, olive oil, and vanilla. In a small bowl, stir together the brown rice flour, tapioca starch, baking powder, and salt and add to the wet ingredients. Whisk together until smooth. Divide the batter between the two prepared pans.
3. In a clean bowl of a stand mixer, beat the egg whites with a whisk attachment until soft peaks form. While continuing to beat, add the remaining 1 cup (200 g) sugar, one tablespoon at a time, until meringue glossy and somewhat stiff, but not holding a stiff peak. Divide the meringue in half and spread over each one of the cakes. Sprinkle the tops with the sliced almonds.
4. Bake until lightly browned, about 25 to 30 minutes. Let the cakes cool in the pan for 20 minutes, then loosen the edges with a knife and gently remove cakes from pans. Be careful not to smash the meringue too much. It’s ok if it cracks slightly. Cool the cakes completely on a wire rack.
5. To assemble the cake. Place one of the cake layers on a platter. Spread whipped cream over the top and spoon the rhubarb over the cream. Add the second cake layer on top and dust the whole thing with powdered sugar. Serve immediately.