Preheat your oven to 350°F (180° C), then line a cookie sheet with parchment paper, or a silicone mat, and set aside. The number of batches will depend on how large/small you want your cookies.
Mix the chopped pecans and melted butter in a small mixing ball. Place the pecan in the prepared baking sheet and bake for 8-10 minutes, or until the pecans are slightly golden and fragrant. Remove from the baking sheet and set aside.
Combine the flour, cornstarch, baking powder, salt and cinnamon in a medium-sized bowl and set aside.
Cream the butter and sugars together in a large bowl with an electric mixer on medium speed until fluffy. Add cream cheese and vanilla and mix until well combined.
Add the flour mixture and mix until the dough comes together and is combined. Stir in roasted pecans. Do not over mix.
Drop by rounded tablespoon onto the prepared baking sheet. For evenly sized cookies use a small spring-loaded ice cream scoop to spoon out the dough. Firmly press a pecan half on top of each ball of cookie dough, if desired
Bake for 8-10 minutes, until very lightly colored on top and around the edges. Allow to cool on baking sheet for 5 minutes, then transfer to a wire rack to cool.