Whip room temperature egg whites and cream of tartar with the whisk attachment of an electric mixer, until the whites begin to foam. Slowly pour in the white sugar and begin to whip the whites on high. Meanwhile, pulse your almond flour, dried strawberries and powdered sugar in a food processor until the mixture is well combined and the texture of flour. Sift this flour mixture through a sieve and throw away the pieces that are too large to pass through the sieve. When the whites have whipped into stiff peaks, fold the almond/sugar mixture into the whites, gradually and carefully until they reach proper “macaronage.” You can find videos online to show you this texture. It's a somewhat thick, glossy texture (not too thin and not too thick).
Spoon the batter into a piping bag with a circular opening (about medium size works great).
Pipe the circles onto a silpat form or parchment paper, using a template, if desired. Pipe the circles by holding the bag straight up and down and vertical to the pan. Squeeze out only enough to fill a circle about the size of a quarter. Do this with each cookie trying to keep them all the same size.
Once the cookies are all piped onto the cookie sheet, slam the cookie sheets 15 times on the counter to dislodge air bubbles. Do this by bringing the pan about 18 inches from the counter and dropping the pan straight down. This step seems silly but will help get all of the bubbles out of the cookies.
Allow the cookie circles to dry for AT LEAST 20 minutes before baking. Preheat oven at 300 degrees for 20 minutes, one sheet at a time, in the center of the oven (move oven racks, if necessary).
Cook until you can touch the top of the cookie and it has a hard ‘crust’. Do not open the oven until the 20 minutes are up. When your macarons are done, they should feel “firm on their feet.” Remove entire silpat or parchment paper onto the counter to let the cookies cool completely. They are super fragile to be careful when transferring the cookies from the pan to the counter. Make sure the macarons are completely cooked before removing shells from the silpat/parchment paper.
For the filling, in a separate bowl, whip the whipping cream with an electric mixer until firm peaks form. Add the powdered sugar and the crushed strawberries. Once the cream is thick you can spoon the mixture into another piping bag and pipe a portion of the cream on one side of the cookie. Place a second cookie on the top so you have little macaron sandwiches. You can also fill these macarons with your favorite jam, nutella or other fillings of your choice. Keep the cookies in a cool, dry place until ready to serve.