Blend all cream cheese sauce layer ingredients into a smooth sauce. Transfer into a jar and chill in the freezer for 15-20 mins while working on the next step.
Preheat oven to 350F. Process all crust ingredients in a food processor until the mixture begins to form a ball (note if the mixture is too runny, add a bit more flour, if too dry, add a bit more maple syrup). Form the mixture into a ball with your hands and knead briefly, then flatten into a disk. Roll the disk out with a rolling pin in between two sheets of parchment into a rough circle that's about ¼" thick.
Discard the top piece of parchment. Spread the "cream cheese" mixture evenly over the crust, leaving a 1" border unfrosted all around the edges. Then spoon the orange marmalade over the cream cheese layer by spoon-fulls and then smooth it out with a spoon to create an even and somewhat marbeled effect. Carefully fold up the unfrosted crust rim over the galette all around the edges to create a rim. If using: gently press some sliced almonds into the crust and sprinkle the center with black sesame seeds.
Transfer the galette carefully along with the parchment paper it's on onto a baking sheet. Bake in a pre-heated oven for 45 mins. Chill completely on a cooling rack and enjoy! (I recommend eating it the day of as the crust will become moist after a day or so).