1. First sift the almond flour, powdered sugar, and salt back and forth twice between two bowls using a mesh strainer. Alternatively you can pulse a few times in a food processor as well. Set aside.
2. Line two baking sheets with parchment and place the templates underneath if using. Set aside.
3. In the bowl of a stand mixer fitted with the whisk attachment, add in the egg white and whisk until slightly foamy about 30 seconds on medium speed. Add in the cream of tartar and whisk until soft peaks appear. Then slowly pour in the sugar. Whisk on high until stiff peaks form, about 1-2 minutes more.
   
4. Remove the bowl from the mixer.
5. Sift half of the dry mixture into the egg whites and fold until barely incorporated, about 10 turns. Repeat with remaining dry mix. Fold until batter forms a ribbon when dropped into bowl.
6. Add 1/2 of the batter into a piping bag and pipe out the white heart shapes, banging the sheet pan on the counter 2 or 3 times to remove any air bubbles.
7. Next add two drops of red food coloring into the batter still in the bowl. Mix until no white streaks remain. (Batter will look light red in color but will bake bright red when finished.)
8. Pour the red batter into a new piping bag and cut the tip off the bag. Pipe out the red hearts, banging the sheet pan on the counter 2 or 3 times to remove any air bubbles.
9. Let both sheets of hearts rest 45 minutes on the counter. Do not cover.
10. Preheat your oven to 350°f. Place cookies in oven to bake, and lower the temperature to 300°f. Cook for 17-18 minutes.
    
11. Let the macarons cool at least 20-30 minutes before filling.

For the buttercream:

1. First make the Swiss strawberry buttercream frosting by whisking the egg whites, sugar, and salt together over a double boiler (or bowl set over simmering water on the stove), until temperature reaches 160°f.
2. Pour heated egg whites into the bowl of a stand mixer and beat until stiff peaks form.
3. When the bowl is cool to the touch, add the butter, one piece at a time, whipping between pieces to incorporate butter, but not fully mixing it in.
4. Next, add in vanilla and strawberry jam. Whip everything on high until smooth.

To decorate:

1. Place the frosting in a piping bag and pipe out along inside edges of the white macarons, leaving a center well to fill with the jam. *You may have leftover frosting. Storage instructions in notes below.
2. Fill the wells with a small amount of jam.
   
3. Place red hearts on top of the filled white hearts.
4. Then, over a bowl, sprinkle heart decorettes on the outside of the macarons where the frosting is. Set aside and repeat until all macarons are decorated. Enjoy!