For the Chocolate Cookies:
In medium mixing bowl, combine flour, baking soda and salt. Set aside.
In large microwave-safe mixing bowl, melt dark chocolate chips and butter. Stir mixture every 20 seconds until chips and butter are completely melted and smooth.
Add brown sugar to chocolate mixture and mix using a wire whisk. Whisk in eggs and vanilla until just combined. Whisk in flour mixture until just combined. Cover and place dough in refrigerator for at least 30 minutes.
Preheat oven to 350°F.
Butter or line baking sheet with silpat or parchment paper.
Drop cookie dough onto baking sheet by rounded tablespoonfuls or using #40 cookie scoop. Cover and refrigerate remaining cookie dough until ready to bake. Bake 9-11 minutes or until edges have begun to set.
Place baking sheet on cooling rack and let cookies rest 5 minutes before transferring cookies to another cooling rack to cool completely. Repeat with remaining cookie dough. Once cookies have been baked and cooled, match them up in pairs.
For the Peppermint Cream Filling:
In medium mixing bowl, use electric mixer to blend cream cheese and butter until smooth and fluffy.
In medium microwave-safe bowl, melt white chocolate chips, stirring every 20 seconds until chips are smooth. Add melted white chocolate, confectioners' sugar and peppermint extract to cream cheese mixture. Beat until completely combined.
Use piping bag fitted with large round tip or a spoon to place peppermint cream onto one cookie in each pair. Place other cookie in pair on top.
For the Dark Chocolate Peppermint Ganache:
In medium microwave-safe mixing bowl, add dark chocolate chips, heavy cream and peppermint extract. Microwave mixture, stirring every 15 seconds until ganache is smooth and shiny. Place in freezer for approximately 10 minutes until ganache has thickened. Use spoon to pour ganache over cookies. Top with peppermint chips and serve. Store any leftover cookies in refrigerator in air-tight container.