Preheat the oven to 325°F. Line an 8-inch round cake pan with parchment and grease the sides.
Make the crumb by mixing almond flour, allulose, butter, vanilla extract, and cinnamon with a fork until small clumps form. Chill while you make the cake batter.
Whisk the almond flour, coconut flour, baking powder, and salt in a medium bowl.
In a large bowl, whisk the eggs, allulose, Greek yogurt, melted butter, and vanilla extract until smooth. Stir in the dry ingredients until the batter is thick and even.
Spread the batter into the pan. Scatter the raspberries over the top, then sprinkle the chilled crumb evenly over the berries.
Bake for 34 to 40 minutes, until the crumb is golden and the center is set. Cool for at least 30 minutes before serving so the crumb holds its texture.