Place the strawberries and sweetener in a medium saucepan over medium heat and stir to combine. 

Let the mixture simmer gently for 15-20 minutes, stirring occasionally and mashing the berries as it thickens and becomes glossy. If needed, reduce the heat.

The sauce is ready when it coats the back of a spoon. Let it cool, then run your finger through the middle; it should leave a clear mark.

Transfer to a heatproof container, allow it to cool, then refrigerate to chill completely.

Preheat the oven to 350°F 

Separate the egg yolks from the whites, making sure no yolk gets into the whites.

In a medium bowl, whisk the almond flour to break up any lumps. Add the salt, then sift in the all-purpose flour, protein powder, and baking powder. Whisk to combine and set aside.

Using a stand or hand mixer, beat the egg yolks, 1/2 cup of sweetener, and vanilla on medium to medium-high speed until smooth, thick, fluffy, and pale yellow, about 2-3 minutes. Transfer to a large bowl, then mix in the buttermilk and set aside.

Clean and dry the same mixing bowl used for the yolks thoroughly. Using the whisk attachment, whip the egg whites on medium to medium-high speed until soft peaks form. Gradually add the remaining 1/2 cup of sweetener and continue whipping until stiff peaks form.

Give the yolk mixture a quick stir. Fold in the sifted ingredients in two additions until well combined. Then, gently fold in the whipped egg whites in three additions, fully incorporating each before adding more. Be careful not to deflate the fluffiness. The final batter should be smooth and airy.

Pour the cake batter into the prepared, greased 10x13-inch baking pan (excluding the handles). Even out the top with a mini spatula.

Bake the cake in the center of the oven for 35 to 40 minutes, or until golden brown and a toothpick inserted into the center comes out clean.

Halfway through baking, gently rotate the cake to ensure it bakes evenly. Be careful not to deflate it. If it’s browning too quickly, loosely cover it with a piece of aluminum foil to give it time to finish baking.

In a medium saucepan, combine the three milks, sweetener, and vanilla. Stir over medium-low heat until the sweetener dissolves, about one minute. Transfer to a separate container, allow it to cool to room temperature, then refrigerate to chill further.

Remove the cake from the oven and let it cool completely. Once cooled, run a spatula around the edges to loosen it. Poke holes all over the surface with a fork, then pour the milk mixture evenly over the cake, including the edges.

Place the cake in the refrigerator and allow it to soak in the milks for at least two hours, or overnight for better flavor and soaking.

Whip the heavy cream and sweetener with the whisk attachment on medium-high speed until medium peaks form.

Spread the cold jam evenly over the top of the chilled, soaked cake.

Add the Chantilly cream to the cake no more than 2 hours before serving, or just before serving, to maintain its structure.

Using a pastry bag with an open star tip, pipe the Chantilly cream around the edges of the cake and create horizontal lines across, allowing parts of the jam to show through. Decorate with more berries and enjoy!