Prep the pan and oven: Heat oven to 350°F (175°C). Line an 8-inch square pan with parchment, leaving overhang for easy lifting.
Lightly grease the sides.
Mix dry ingredients: In a large bowl, whisk almond flour, oats, protein powder, coconut sugar, baking powder, baking soda, and salt until no lumps remain.
Whisk wet ingredients: In a separate bowl, whisk Greek yogurt, eggs, applesauce, maple syrup, vanilla, and melted coconut oil until smooth.
Combine: Pour wet into dry and stir with a spatula just until combined. The batter will be thick but spreadable.
Make the raspberry layer: In a small bowl, gently toss raspberries with lemon juice and cornstarch. Lightly crush about a third of the berries with the back of a spoon to release some juice.
Layer it: Spread about two-thirds of the batter into the pan in an even layer.
Scatter the raspberry mixture over the top. Dollop the remaining batter over the fruit in small spoonfuls, leaving some raspberries exposed for a jammy look.
Add crunch: Sprinkle sliced almonds over the surface. Add a light dusting of coarse sugar if you like a bakery-style finish.
Bake: Bake 28–34 minutes, until the top is lightly golden and the center springs back when touched.
A toothpick should come out mostly clean (a little raspberry on it is fine).
Cool and slice: Let the pan cool on a rack for at least 30–45 minutes. Use the parchment to lift the slab out. Cut into 12 bars for snacks or 9 larger squares for dessert.