In a bowl, combine the dry ingredients until combined. Set aside
In a large bowl, whip the softened butter and sugar until light and fluffy, about 4-5 mins. Add the eggs and vanilla and mix until combined.
Fold the dry ingredients into the wet until combined. The mixture should not be too wet or sticky. Using a ⅓ cup measuring cup or large ice cream scoop, measure out the dough and place it into your palm.
Use your thumb to press into the center of the dough, creating a little well. Add a slight spoonful of corn kernels and fold the edges of the dough around the center to enclose it. Roll into a ball. Repeat then chill overnight.
Preheat an oven at 350F and place a rack in the center of the oven. Bake cookies for 12-14 mins or until golden brown. Let cool for 10 mins.
While cooling, make the lime buttercream frosting. Cream the butter until smooth and fluffy. Add ½c powdered sugar at a time then beat until combined, repeat. Add then lime juice and salt. Beat until combined once more.
Pipe on cooled cookies. Garnish with lime zest and tajin. Serve
