Crust: preheat oven to 350 degrees. Mix graham crackers and brown sugar in food processor until they are a fine crumb. Melt butter and add to crumb mixture and pulse in food processor until combined. Pour into springform pan. Press firmly along bottom and sides to make an even crust. Bake for about 15 minutes (until it starts to brown). Allow to come to room temperature, then refrigerate.

Chocolate Ganache: In a small sauce pan bring cream and butter to a boil. Add chocolate to a bowl and pour liquid over the chocolate. Let sit for 5 minutes then whisk until it is smooth. Pour over crust and rotate so it covers the bottom and sides. Put chocolate covered crust in fridge to cool and solidify overnight.

Butterscotch Pudding: Melt butter in a sauce pan. Once melted, whisk in the brown sugar and cook until melted and bubbly. Reduce heat to low and gradually add in heavy cream. Stir until fully combined. Whisk in milk and salt. Set pan aside until room temperature. In a small bowl, put 2tbsp of water and sprinkle gelatin on top. DO NOT MIX. Set bowl aside and let gelatin bloom.

Butterscotch Pudding: In a separate bowl, whisk cornstarch with 1/4 cup of water then add into room temperature butter mixture. Put back on stove over medium/high heat and mix until thick. Reduce heat to low and stir briskly for 1 minute. Remove from heat. Slowly stir in gelatin mixture and add vanilla. Whisk until smooth. Cover with plastic wrap and refrigerate overnight.

Chocolate Mousse: bring 1/2 cup heavy cream and vanilla to a boil. In a bowl, add chocolate and pour cream over the top. Let sit for 5 minutes then whisk until smooth and cool to room temperature stirring occasionally. In a separate bowl, beat remaining cream until whipped and forms soft peaks. Add sugar over cream and continue beating until thick. Slowly fold in chocolate mixture.

To Assemble: add butterscotch Pudding into chocolate covered crust and smooth. Pour mousse on top and smooth. Refrigerate for at least 6 hours. Remove from springform pan and serve!