COOKIE:
Put flour, baking soda and salt in medium bowl and mix to combine.
In bowl of mixer cream the butter until light and fluffy.
Mix in the sugar and mix until pale yellow.
Add in the egg and vanilla, mix until combined.
With mixer on medium slowly drizzle in the melted chocolate, continue mixing until fully combined.
Scrape down the sides of the bowl as needed.
With mixer on low speed slowly add in the flour mixture and mix until well combined and dough forms.
Turn out dough onto lightly floured surface and form into a bowl and flatten into a disk.
Wrap in plastic wrap and refrigerate for at least 60 minutes.
When ready to roll out place dough between two pieces of parchment and roll out to 1/4 inch thick.
Transfer dough to refrigerator and chill for 60 minutes.
Preheat oven to 350 degrees F.
Cut out cookies and place on parchment lined baking sheet, 1 inch apart.
Transfer to refrigerator for 15 minutes to stiffen up the dough.
Bake until cookies are slightly firm to the touch. About 10 minutes.
Let cook completely.
GANACHE:
Bring heavy cream to just a boil, pour over chocolate in a small mixing bowl.
Let set for 60 seconds, start stirring in small circular motions until chocolate starts to melt.
Stir in larger circles to fully mix the chocolate and heavy cream until ganache forms. *
Let cool slightly.
ASSEMBLY:
Layout your cookie pairs (tops and bottoms).
On the bottom cookie spoon on ganache leaving a 1/4 inch edge around the cookie.
Place the top cookie on and press slightly together.
Repeat with all the cookies.
Let set until ganache is fully set, 3 hours minimum.
GARNISH (optional):
Have your cookies in front of you.
Dip one side of cookie into melted chocolate**
Lay on parchment lined cookie sheet, sprinkle with sprinkles.
Repeat with all cookies sandwiches.
Let set completely.