Preheat your oven to 350°F and lightly grease a standard-sized ceramic ramekin with a small amount of coconut oil.
In a medium mixing bowl, whisk together the chocolate protein powder, almond flour, cacao powder, baking powder, sea salt, and monk fruit sweetener until no lumps remain.
Add the egg whites and Greek yogurt to the dry ingredients, stirring until the mixture forms a thick, uniform batter.
Pour approximately two-thirds of the batter into the prepared ramekin.
Place the almond butter directly into the center of the batter, then cover it with the remaining chocolate batter to seal the core.
Bake for 12 to 14 minutes; the edges should be firm and set, while the center should remain slightly soft and jiggly to the touch.
While the cake bakes, combine the raspberries, lemon juice, and water in a small saucepan over medium heat.
Muddle the berries with a fork and simmer for 5 minutes until the sauce thickens into a glossy coulis, then strain if a smoother texture is desired.
Allow the cake to cool in the ramekin for 2 minutes, then carefully run a thin knife around the edge and invert it onto a plate.
Drizzle the warm raspberry coulis over the top of the lava cake and serve immediately.