Preheat oven to 300F. Line sheet tray with Silpat or parchment paper. Chop almonds if not already prepared.

Combine almond flour and chopped almonds in a bowl. Mix well until blended. Set aside.

Combine egg whites and cream of tartar in a mixing bowl.

Using a wire attachment, on medium, mix until foamy. Increase speed then gradually add Allulose. Look for medium stiff peaks. Note that, because we are not using sugar, the meringue will not whip to stiff peaks.

Carefully fold the almond flour and chopped almond mixture into the meringue until thoroughly combined.

Evenly distribute mixture into three ring molds or pipe into three equal rounds. Smooth the surface until even using an offset spatula.

Bake in the center of the oven for 30 minutes or until golden. Cool and set aside. Note that this may be made ahead of time. To store, wrap in plastic wrap and refrigerate.

In a heavy bottomed saucepan, combine water and Allulose.

Set up a candy thermometer, if using. Set the saucepan over low heat and allow to cook to soft ball stage or 240F.

Meanwhile, while the syrup is cooking, combine egg yolks and vanilla in a bowl.

Using a wire whisk, whip on high until light and doubled in volume, approximately 8 minutes.

When the syrup reaches 240F (softball stage), remove from heat. Reduce mixer speed to low. In a slow, even stream, away from the whisk, gently pour in the syrup. Continue until all the syrup has been added.

Transfer to another container and let cool. Note that this may be made ahead of time. To store, refrigerate in an airtight container.

Place the butter in a mixing bowl. Using a paddle attachment, cream butter at low speed until soft. Occasionally scrape the bottom and sides of the bowl. Increase speed to medium and continue to whip until volume increases.

Turn mixer off. Add the syrup and, on low speed, continue to mix until the buttercream is light and smooth.

Layer dacquoise and buttercream alternately.

Frost the entire cake with the buttercream. Additional chopped almonds can be added for garnish, if desired.