Preheat your oven to 350°F (175°C). Grease a 9-inch (23 cm) round baking dish or tart pan and set it aside.
Peel, core, and thinly slice the apples. Place them in a bowl and toss them with the lemon juice to prevent browning. Set aside.
In a large mixing bowl, beat the eggs and granulated sugar together until the mixture becomes light and fluffy.
In a separate bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the egg and sugar mixture, alternating with the milk. Start and end with the dry ingredients. Mix until you have a smooth batter.
Stir in the vanilla extract.
Pour the batter into the prepared baking dish.
Arrange the sliced apples on top of the batter in a decorative pattern. You can place them in concentric circles or any design you prefer.
Bake in the preheated oven for about 45-50 minutes or until the top is golden brown and a toothpick inserted into the center comes out clean.
Remove the tart from the oven and let it cool in the pan for about 10 minutes.
Once slightly cooled, you can dust the top of the tart with powdered sugar and a sprinkle of ground cinnamon if desired.
Serve the Spanish Tarta de Manzana warm or at room temperature. It's delicious on its own or with a scoop of vanilla ice cream or a dollop of whipped cream.