Mix the active dry yeast in slightly warm milk and stir well. Let it rest for a few minutes.
If kneading by hand: In the meantime, add the flour, sugar, salt, vanilla, orange zest, and olive oil to a bowl and mix with a spoon. Add the milk, mix with a spoon, then start kneading the dough by hand for at least 10 minutes until it is nice and smooth. The dough should be pretty sticky to begin with. If it feels a bit too dry, add a touch more milk. Avoid adding more flour, and if you need help handling the sticky dough, use some extra olive oil on your hands.If using a mixer: Add all the ingredients to a stand mixer bowl with the dough hook. Knead for at least 10 minutes or until the dough is smooth, soft, and elastic. Shape the dough into a smooth ball, place it back into a clean bowl greased with a bit of oil, and cover it with a slightly damp tea towel or a lid (this will prevent the dough from drying out). Place the dough in a warm place (I usually place it in the microwave or the oven with the light bulb turned on) and wait for it to double in size. It should take at least 1 hour to 1 hour and a half.
Take the dough out of the bowl and divide it into 8 equal-sized pieces. You will use 6 pieces to make the bunny head and 2 pieces to make the ears. Shape 6 pieces into smooth balls and place them on a baking tray covered with parchment paper. Make sure to space the balls well, as they will grow in size.
Divide the last 2 balls into 3 smaller balls each, cut them in half to form the ears, and place them on each dough ball.
Cover again with the tea towel and leave it in a warm place to rest for 30-40 minutes. The dough should increase by 50%.
In the meantime, preheat the oven to 340 F (170 C).
Brush the bunnies with almond milk. Bake in the oven for 12-14 minutes or until the top is golden. If the bunnies are browning too quickly, you can cover them with aluminum foil.
While the bunnies are baking, make the sugar syrup. Add the sugar and water to a pot on medium-high heat and bring to a boil. Reduce the heat and let it simmer for a few minutes until you reach a syrup consistency.
Remove from the oven (note 6). While the brioche bunnies are still warm, brush the top with the sugar syrup. Decorate the ears with pearl sugar. Melt the chocolate. Once they've cooled down a bit, decorate the bunnies with eyes and nose with the help of a toothpick.
Serve the bunnies warm or at room temperature. Store the brioche bunnies in an airtight container at room temperature for up to 3 days or in the freezer for up to 1 month. To serve the brioche bunnies, reheat for a few minutes in the oven.