In a large bowl, gently combine apples with sugar, lemon zest, lemon juice, vanilla, cardamom and flour.
Gently unfold and lay out pie crust on a baking sheet lined with parchment paper.
Pour the apple mixture in the center of the unfolded pie crust leaving a 2-inch border. Arrange the apples in overlapping rows or circles. Fold up the uncovered border over the edge of the fruit and pinch into pleats.
Whisk egg and, using a pastry brush, brush the egg onto the crust and sprinkle with almonds and sugar.
Bake until apples are tender and the crust is golden, 35 to 40 minutes.
Remove from oven, let sit for 5-10 minutes, serve with a scoop of ice cream on top and enjoy!