Preheat the oven to 400 degrees. Line a sheet pan with parchment paper (you'll need 2 sheet pans for smaller scones). Set an oven rack on the middle level of the oven.

Measure 1 cup heavy cream and place it in the freezer for 10 minutes. Place the butter in a microwave-safe bowl, cover with a paper towel and heat on high for 1 minute. If not completely melted, return to the microwave for 10-second intervals till melted. Set aside to cool a bit while prepping other ingredients.

Whisk flour, sugar, corn starch, poppy seeds, baking powder, baking soda, salt and lemon zest in a medium-size bowl. Stir to combine and set aside.

After heavy cream has been chilled in the freezer for 10 minutes, combine it with the melted butter. Stir with a fork until butter forms small clumps or globules.

Add the cream mixture to the dry ingredients and stir with a rubber spatula until all flour is incorporated. The batter will be very thick, like a cookie dough.

Spray a cookie scooper or large spoon with non-stick cooking spray. Scoop up scones in mounds onto the prepared pan. Space the scones at least 2 inches apart to allow for some spreading.

Refrigerate unbaked scones for at least 15 minutes.

Bake for 12 minutes then check for doneness. When scones are light golden brown, remove them from the oven and transfer to a wire cooling rack.

While the scones are baking, make the lemon glaze. Combine the powdered sugar, milk (or half and half) and lemon juice in a medium-size bowl. Whisk well until smooth.

Place a sheet pan or piece of foil under the cooling rack and spoon the glaze over scones to cover completely. Sprinkle each scone with extra poppy seeds for a pretty presentation.

Let the glaze set before serving.