For the Fondant:
1 1/2 cups water
1/2 teaspoon cream of tartar
4 1/2 cups white sugar
2 tablespoons lemon juice
For the Sponge:
3/4 cup milk, room temperature, divided
1 1/2 (0.6 ounce) cakes cake yeast
1 teaspoon white sugar
1 cup unbleached flour
For the Dough:
3 cups unbleached flour
1/4 cup white sugar
1 pinch salt
2 eggs, room temperature
zest from 1 lemon
3/4 cup unsalted butter, room temperature and cut into chunks
1/2 cup ground almonds
For the Filling:
3/4 cup milk
3 tablespoons unsalted butter, at room temperature
1/3 cup white sugar
2 1/2 cups poppy seeds
1 1/2 teaspoons lemon zest
1/2 teaspoon ground cinnamon
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