• Preheat your oven to 350°F. Grease and flour two 8-inch round cake pans and set aside.
• In a medium bowl, whisk together the flour, baking powder, and salt until well combined.
• In a large mixing bowl, beat the butter and sugar together until light and fluffy. Add the eggs one at a time, beating well after each addition.
• Gradually add the flour mixture to the butter mixture, alternating with the milk and vanilla extract.
• Divide the batter evenly among the two cake pans. Bake for 20-25 minutes, or until a toothpick inserted into the center of the cakes comes out clean.
• Let the cakes cool completely on wire racks.

For the mango mousse:

• In a medium saucepan, combine the mango puree, sugar, and water. Bring to a boil over medium-high heat, stirring occasionally.
• Reduce the heat to low and simmer for 5 minutes, stirring occasionally.
• In a small bowl, sprinkle the gelatin powder over 1/4 cup of cold water. Let it sit for 5 minutes to soften.
• Add the gelatin mixture to the mango mixture and stir until the gelatin is completely dissolved. Set aside to cool.
• In a large mixing bowl, whip the heavy cream until stiff peaks form.
• Gently fold the cooled mango mixture into the whipped cream until well combined.

To assemble the cake:

• Place one cake layer on a cake stand or serving plate. Spoon 1/3 of the mango mousse over the cake layer and spread it evenly.
• Place another cake layer on top of the mousse and repeat with another layer of mousse.
• Chill the cake in the refrigerator for at least 2 hours before serving.
• Enjoy your delicious layered mango mousse cake!