Gather ingredients for the sweet shortcrust pastry. Combine flour and sugar, then cut-in butter. You can use your hands to smush it around until the butter is incorporated into the flour. It should be crumbly, with some flakes of butter visible. Add in the egg yolk and start with 1 tbsp of water. The dough should start sticking together. Continue adding water if you need to until the dough sticks together in one ball, but is not tacky or wet feeling. Wrap in siran wrap and let chill in fridge for 20-30 minutes.
Gather ingredients for creme patissiere. With a hand mixer, beat together egg yolks and sugar until the mixture is a pale yellow color. Then beat in the cornstarch and set aside. In a medium sized pot, bring milk and vanilla to a boil over medium heat. Once milk is boiling, gradually pour ¼ cup into egg yolk mixture while whisking until incorporated. Then pour all of it back into the pot and whisk continually over low heat until it thickens. Once its thick, pour into a bowl and cover with siran wrap right on the top of the cream so it doesn’t form a skin and stick in fridge to cool. It might take an hour or two.
Take shortcrust dough out of fridge and roll out on a lightly floured surface. Grease a 9″ tart or spring form pan and line the pan with your dough and cut to fit. Place a layer of parchment paper over crust and fill either with ceramic baking weights or uncooked rice. Bake at 350°F for 10 minutes. Remove weights and parchment paper, then bake for another 10 minutes, until golden and let cool.
Gather ingredients for the chocolate mousse. Beat avocados in a food processor, or blender. Add sifted cocoa powder and confectioner’s sugar and blend together. Add in coconut milk and sea salt and blend. Add in melted chocolate as you’re blending until nice and smooth.
Once creme patisserie is cooled, add orange zest and mix together.
Spread a modest layer of raspberry jam on the bottom of your crust. Next plop creme patissiere all around on top of the jam and carefully spread all over until you have an even layer. Finally spread chocolate mousse on top with the same technique, plopping spoonfuls all around and then carefully spreading it on. When you have a nice flat top, assemble two rows of fresh raspberries around the edge and place an orange slice in the middle. Zest an orange over the top to your liking. Store in refrigerator.