Preheat oven to 350F and line a cupcake pan with 12 parchment liners.
In a medium-sized bowl, whisk together the almond flour, cornstarch, poppy seeds, baking powder and salt.
In a large bowl, use an electric mixer on medium-high speed to beat together the eggs and sugar until bubbles form on top, about 1 minute.
Add in the oil, lemon zest, lemon juice and almond extract. Mix until just combined.
Add the dry ingredients to the wet mixture, switch to a spatula, and stir until just combined.
Divide the batter into the 12 cupcake liners, filling each one about ¾ full.
Bake for 13-15 minutes, or until a toothpick inserted into a cupcake comes out clean. Let cool for 5 minutes in the pan, then transfer to a wire rack to cool completely.
Cut a circle into the top of each cupcake, about 1-inch deep. (You can use a knife, but I normally use the bottom of a piping tip to carve it out).
Spoon or pipe some of the lemon curd into each of the carved out circles. (You'll use about half of the curd).
Make the frosting:
First, whip together the cold cream cheese and lemon juice and then beat in the powdered sugar. The mixture should resemble runny cream cheese frosting.
On low speed, gradually add in the cold whipping cream until it's mixed into the cream cheese mixture. Once everything is combined, increase the speed to medium-high and beat until stiff peaks form.
Pipe the frosting onto the cupcakes, leaving a center in the middle and then spoon or pipe in the remainder of the lemon curd.
Notes
Be careful not to over whip the sugar and eggs. You just need to beat them together for about a minute in order to get the mixture foamy with bubbles on top. If you whip them for too long, the mixture will increase in size. This will add too much liquid to the batter and make it too runny.
Let the cupcakes completely cool. In order to carve out centers for the lemon curd, you need the cupcakes to be fully cooled. This is also important for the whipped cream topping. It will just melt off if the cupcakes are still warm.
Making the frosting. Be careful not to overmix. Once you hit stiff peaks, stop the mixer. The frosting can quickly curdle if you whip it for too long.