In a mixing bowl, beat the ¾ cup butter, ¼ cup vegan shortening, and 1 cup sugar until creamy and lightly whipped.
Add the vegan egg and 1 tablespoon vanilla extract and beat until combined.
In a medium mixing bowl, whisk the 2 ½ cups all-purpose flour, ½ teaspoon baking soda, ½ teaspoon baking powder, and ¼ teaspoon salt until combined.
Add the flour to the butter mixture and slowly beat until just combined.
Roll into 1-inch (1 tablespoon) balls and flatten into discs. Place on a cookie sheet.
With a teaspoon or your thumb, press indentations into the center of the cookies and fill with the lemon curd.
Bake for approximately 12 minutes or until the bottom of the cookies are a light golden brown.
Cool on the cookie sheet for a few minutes, then transfer to a cooling rack until completely cooled.