Preheat oven to 350 F with a rack in the middle position. Lightly grease a 8x8 inch pan, cover with foil (or the baking paper). Push the foil into the corners and up the sides of the pan, using 2 pieces if necessary to ensure that the foil overlaps all edges (the overhang will help removal from the pan). Spray the foiled pan with nonstick cooking spray or brush with melted butter.

In a food Processor place the flour, cornstarch, baking powder, 1/2 cup sugar, pinch of salt, process on medium speed for a few seconds.Add the butter and mix to blend for 10"-15" until the mixture resembles coarse meal, pale yellow but to stop before the mixture turns into a ball!Put the dough into the bottom of the prepared pan and press down firmly to form an even layer & compact with the help of a cup.Prick with the fork all over.Bake the crust for 20'-25' until the edges turn golden brown.

Meanwhile waiting for the crust to cook, prepare the Lemon Fillings cook on a heat proof small bowl: place in the bowl 4 eggs, the eggs yolks & soft brown sugar stirring frequently.On a very low heat, whisk in the 3/4 cup-1 cup lemon juice, 3 tbs lemons zest & salt to form a smooth liquid mixture, stirring constantly.(Option: to thicken with 1tbs flour).Dont leave the mixture alone!!Set a small strainer over a mixing bowl&place next to the stove.It's ready to go when the curd is done cooking.

The pan with the Lemon mixture: Stir gently, but continuously until the mixture thickens enough to coat the back of the spoon & register 170 F on an instant-read thermometer; this should take 10'-12'. Be sure to scrape the bottom & edges of the pan as you stir. If you notice the mixture starting to coagulate and clump up, immediately remove the pan from heat.Strain the lemon curd into the bowl,removing the zest & any clumps from the curd. While the curd is still warm, stir

In the butter. Stir until the butter is completely melted. Once the shortbread crust is done cooked in the oven, remove it and put on the working table and immediately pour the Lemon Filling over top of the hot crust. Return the pan back to the oven and bake at 350 F for 10-15 more minutes or until the edges of the curd is set, but the middle is still jiggly.

Then remove the pan from the oven and place on the counter to cool. To slice: Sprinkle the tops bars with Icing sugar powder, then cover and transfer to the refrigerator and let the bars chill for at least 4 hours.Then starts cut into large squares using a chef knife cut around the edge first,then lift them onto a cutting board using the flaps of foil.Cut straight down into bars.😊To serve the square cold with a dullop of whipped cream and a cup of coffee or with a cup of hot ginger tea! 🍋🍸☕😍

To make the Lemon Curd on its own: cook it on the stove top, strain and stir in the butter as directed. No need to bake. Transfer the curd to a small glass jar container with the lid on and refrigerator. Eat within a week.😍