Preheat oven to 350 degrees. Line a rimmed baking sheet with parchment paper.

Slice four 1 ¼-inch slices brioche. In a large baking dish, whisk to combine 4 eggs, 1 cup milk, 1 tablespoon vanilla extract, 3 tablespoons sugar, and ¾ teaspoon salt. Arrange brioche in the egg mixture, flipping a few times. Let soak, continuing to flip pieces occasionally, while you make the frangipane.

Combine 6 tablespoons softened butter and ½ cup granulated sugar in a stand mixer fitted with the paddle attachment. Mix on medium-high speed until smooth. Add 1 cup almond flour, 2 tablespoons flour, 2 teaspoons almond extract, 1 teaspoon salt, and the remaining 1 tablespoon vanilla extract and 1 egg. Mix on medium speed until combined, scraping down the side of the bowl as necessary. Add raspberries and mix to combine.

Melt the remaining 4 tablespoons butter. Add 2 ½ cups Special K Red Berries to a large bowl. Crunch with your hands until broken down into medium-sized crumbs. Add the melted butter and 3 tablespoons sugar. Mix thoroughly to combine.

Transfer the four slices soaked brioche to the baking sheet, spacing them evenly. Divide frangipane among the tops of the four slices. Spread to the edges. Divide Special K crunch mixture onto the frangipane, pressing to adhere. Bake until toasts are puffed and the frangipane is golden on the edges, about 28-32 minutes. Serve, topped with powdered sugar.