Preheat oven to 350° F. Grease a 9" springform pan. Set aside.
In a large heatproof bowl, melt the chocolate and butter in the microwave on 30-seconds burst, stirring after each burst.
Add sugar and salt. Stir to combine.
Add eggs, vanilla extract, and chocolate extract (see note). Stir to combine. Add flour, and mix until just incorporated.
Scrape the brownie batter into the prepared pan. Bake about 20 minutes, or until a toothpick inserted in the center comes out clean. Do not overbake! Allow brownie to cool completely.
For Pie Filling:
In a small heatproof bowl, melt the chocolate chips in the microwave on 30-second bursts, stirring after each burst, until smooth. Set aside to cool.
In a large heatproof bowl, combine hot water, cocoa powder, vanilla bean paste (see note), chocolate extract (see note), and kahlua (see note). Stir to combine.
Add cooled, melted chocolate to the cocoa mixture and stir to combine.
In the bowl of a stand mixer, combine the cream, sugar, and salt. Whip to soft peaks. Gently fold the whipped cream into the chocolate mixture in three additions, taking care to not deflate the cream.
Once no white streaks remain, scrape the filling into the pan on top of the cooled brownie crust. Refrigerate one hour, or until firm.
For Whipped Cream(s):
In the bowl of a stand mixer, combine cream and powdered sugars. Beat to soft peaks.
Divide the whipped cream evenly between three bowls.
For the vanilla bean whipped cream: add vanilla bean paste (see note), and stir to combine.
For the Kahlua whipped cream: add Kahlua (see note) and cocoa powder and stir to combine.
For the chocolate whipped cream: add cocoa powder and stir to combine.
Finishing:
Remove the chilled pie from the springform pan and transfer to a serving plate.
Pipe or dollop whipped cream on top of the pie. Store in the refrigerator.Enjoy!
Notes
Note on chocolate extract: I highly recommend this (sometimes overlooked) extract! It lends amazing depth of flavor to chocolate baked goods! If you can't find it in your local grocery store, you can find some [here]. Even better, make yourself some [Homemade Chocolate Extract] for next time!Note on vanilla bean paste: You know me, it's in everything! Delicious and more economical than whole vanilla beans, this ingredient is my go-to for an extra punch of flavor. You can find it online [here]. If you prefer to substitute, you can use an equal measure of vanilla extract.Note on Kahlua: I used my own [Homemade Kahlua] in this recipe. Store-bought Kahlua is absolutely fine, I just NEED you to know that you can make it yourself. The homemade stuff is SO DELICIOUS!Note on whipped cream: There's no *need* to make three different flavors of whipped cream, that's just how I roll. :D I made one batch of whipped cream, then divided it into thirds and flavored each differently. You do you and make whatever kind of whipped cream you want. The piping also isn't a requirement, of course. Dollop that goodness on with a spoon and dig in!