Grease with butter two 8” [20 cm] non-stick baking pans. Set aside.Heat oven to 350ºF [150 ºC].
Step 2: Combine dry ingredients
In a large bowl, combine flour, baking soda, salt, baking powder, poppyseeds and sugar and set aside.
Step 3: Mixing wet ingredients
Whisk the eggs over high speed with the electric mixer using the wire, until the eggs become lighter and foamy (about 3 minutes). Slowly pour in the oil and beat until it becomes a much lighter color and becomes even foamier (another 3 minutes).Slowly pour in lime juice and beat for another minute, followed by the lemon zest, and the condensed milk – which should also be poured in very slowly. Once it’s all mixed, turn off the mixer.
Step 4: Add dry ingredients
Slowly sift in the flour mix while carefully folding it into the batter using a spatula. It should be made slowly enough that there are no clumps of flour in the batter, and the mix does not lose the air.
Step 5: Bake
Carefully pour the batter into the prepared baking pans, making sure both contain the same amount of batter.Bake in the preheated oven until the top turns golden brown, or a skewer comes out clean when you poke the cake (20-25 mins).Remove from the oven and cool to room temperature prior to removing from the pan.
Step 6: Make frosting
To make the frosting, pour the cream cheese into the mixer bowl and add the sugar. Beat at low speed using the flat beater attachment until it turns into a smooth cream with no lumps.Pour in the heavy cream and beat until it has incorporated uniformly into the cream cheese mix and it turns into a fluffy frosting. Add the lemon zest, and slowly pour in the lemon juice by small amounts until it is well incorporated and has a creamy consistency.Place the cream cheese spread in an airtight container, and store in the fridge for later use.
Step 7: Decorate
For best results, scoop the frosting into a decorating bag with the tip. Make concentric circles on top of one of the cakes to cover with frosting. Top with the other cake and repeat the same operation to cover with frosting. You can use a spatula to even out the frosting, but it should not be very thick.The cream cheese frosting should be thoroughly chilled. You can also spread the frosting thinly around the cake using a decorating spatula; if you find the frosting too firm, let it warm just a bit outside the fridge, so the soft frosting is easier to spread.Maintain the cake chilled till serving time.