These are a little time consuming, but totally worth it!
Move your oven rack to the lower third of the oven. Preheat it to 350 degrees Fahrenheit. Line a cookie sheet with parchment paper, on the back of which you can draw one inch circles to help guide your piping.
Sift the almond flour and confectioner's sugar together into a bowl through a fine sieve. You can put any large pieces of almond flour left behind through a spice grinder and sift again into the bowl.
In a metal mixer bowl, beat 3 large egg whites with the granulated sugar until stiff, glossy peaks form.
Add the vanilla extract, and scrape the seeds from the vanilla bean into the beaten egg whites. beat for 5 seconds to incorporate.
Dump all the dry ingredients into the bowl. Using a spatula, fold the mixture in, using 20-30 strokes. The mixture will be thick, with a consistency similar to a thick milkshake.
Pour the macaron mixture into a piping bag with a large round tip, or snip off the end of a disposable piping bag. You could also use a resealable plastic bag with one corner snipped off.
Pipe the meringue mixture onto your baking sheet, filling int he circles. Let these sit for 20-60 minutes until a skin forms on top. How long this takes depends on the heat and humidity of your kitchen.
Put one pan in the oven at a time. Bake for 10-12 minutes, rotating the pan once halfway through, until the cookies have risen and set, but not browned.
Remove from oven and let cool on the pan.
Chop your dark chocolate fine and place in a heat-safe bowl.
Heat the cream to a simmer on the stove. Remove from heat and pour over the chocolate. Let the mixture sit for one minute.
Stir the chocolate and cream, until it has melted together. Add the butter and amaretto and whisk together until all is incorporated.
Let the mixture cool until it is thick, but still pourable. Pour into a resealable bag or piping bag and continue to let it cool until it reaches a frosting consistency.
Pipe onto the bottom of a macaron cookie, and then cover with a second cookie to make a sandwich.
Wrap any leftover cookies tightly in plastic wrap and store in an airtight container in the freezer.