Preheat the oven to 350 degrees. Spray two 8-inch round cake pans with nonstick cooking spray and line the bottoms with rounds of parchment paper.
In a small bowl combine 1/4 cup milk with the poppy seeds. Set aside.
In a large mixing bowl of the bowl of a stand mixer, whisk together the flour, sugar, baking powder, and salt. Whisk in the lemon zest.
Add the butter and with a mixer, blend the butter into the dry ingredients until it appears grainy and small clumps form.
In a separate bowl, mix together the remaining cup of milk, the two eggs, and the vanilla extract.
Add the liquid to the flour micture in two additions, then stir in the seeds and their milk, beating 15 seconds on medicum after each addition.
Divide the mixture into the prepared pans and bake for 28 minutes or until the cake springs back when lightly touched and a tester comes out with a few crumbs attached.
Cool the cakes on a rack for 15 minutes prior to removing them from the pans and removing the attached parchment paper. Allow the cakes to cool completely.
To frost, place one cake layer on the serving platter. Spoon the lemon curd on top and spread to the edges. Place the second layer on top.
Frost the entire cake with the buttercream frosting. Add sprinkles or decor if you wish.
The cake can be stored at room temperature until serving. If you prefer cold cake, store it in the refrigerator.
Promptly store leftovers in an airtight container and consume within 3 days.Nutritional values are approximate and based on 1 slice of cake. Values do not account for frosting.Adaptation: if you have a white cake mix, you can substitute that for the flour, sugar, baking powder, and salt. Follow the package instructions, using milk and butter for the oil and water, adding milk-soaked poppy seeds, lemon zest, and vanilla extract to the batter.