In a mixing bowl add the softened butter and both sugars. Mix, using a hand mixer or a stand mixer on medium speed for about 1 minute. Use a spatula once or twice around the sides during the creaming process to scrape the sides of the bowl. 

Next add the egg, vanilla extract and almond extract and mix for about 15 seconds to incorporate it into the butter/sugar mixture. 

In a separate bowl, add the flour, unsweetened cocoa, salt and baking soda. Use a whisk to mix the ingredients well. Slowly add the dry ingredients into the butter/sugar mixture. Continue to beat mixture until a dough has formed and no dry ingredients can be seen. 

Next you will want to chill the dough you just made for at least an hour. Once chilled use a rolling pin (dusted with flour) and roll dough out dough about 1" thick. 

Use a small heart shaped cookie cutter to cut dough into heart shapes. Place cut out shapes on a cookie sheet lined with parchment paper. Bake at 350 for 10 minutes. Remove from oven and allow to cool on cookie sheet for 2-3 minutes. Move to wire rack to allow to cool completely. 

Once cookies are cool, take one and add about 1 tablespoon of frosting on the bottom. Place another cookie underneath to create a cookie sandwich. Sprinkle pretty sugar crystals on the outside of the filling to make them pretty!