Preheat oven to 350°F. Have a deep-dish pie plate ready to go.
Place the bread mix into the bowl of a food processor or electric mixer. Scatter the cubed butter over the bread mix. Pulse, if using food processor, about 10 times to work the butter into the flour. If using a mixer, turn on to low speed to work the butter into the flour. It will resemble cornmeal with larger, pea-sized pieces of butter remaining. This can also be done by hand using a pastry cutter and gentle hand.
With the processor or mixer running on low speed, add the ice water to the bowl a little at a time. You may not need all of it. When the dough comes together into a ball, stop the motor. Use a spatula to scrape down the sides. Check to see if it's too dry. If so, add a little more water. It should be soft and pliable, like cookie dough, without being too sticky. Form dough into two small disks. Wrap both and refrigerate for 20-30 minutes to make it easier to work with. (Note: you only need one crust. The other can be frozen or used for another pie.)
Place the chilled dough onto a piece of parchment paper. Place another sheet of parchment paper on top and use a rolling pin to roll the dough into a large round about ¼" thick.
Carefully transfer the dough to the pie plate. If it cracks or breaks, no worries. Just press it back together and continue. Trim off the excess dough from around the edge. Decorate the edge all the way around by pinching it between two fingers, or using another method. Chill until ready to fill and bake. (The pie dough scraps can be saved and rolled out to form pie crust cookies.)
Preheat oven to 400°F. Prick the bottom of the crust with a fork a few times. Place crust in oven and bake for 15-20 minutes, or just until golden on the edges. Let cool for 10-15 minutes.
Lower heat to 350°F. Prepare filling.
Whisk together egg yolks, brown sugar, maple syrup, and cornstarch until the sugar has mostly dissolved. Add the remaining ingredients and whisk well. Pour filling into the partially baked crust. Bake for 45-50 minutes, or until the filling is set, but still jiggles a little in the center. (It may take as long as an hour) Let cool completely. Refrigerate, if desired, or serve at room temperature. Store any leftover pie in an airtight container in the fridge.
Beat the heavy cream with an electric mixer, or by hand with a whisk, until soft peaks form. Add the molasses and vanilla extract. Continue beating or whisking until medium peaks form. Dollop on top of pie.