Preheat the oven to 350°F. Line a large baking sheet with parchment. Combine the flour, baking powder, salt, and 1/3 cup sugar in a medium-size mixing bowl. Stir with a fork to combine.
Grate the cold butter and add the butter shreds to the flour mixture. Use a fork to mix the butter into the flour until it's evenly dispersed and approximately pea-sized.
Stir together 1/3 cup heavy cream, maple syrup, and vanilla. Add the liquids and stir until a loose, dry dough forms. Add additional cream, only if needed. Gently fold in the pecans. Use a medium scoop to portion 12-18 balls of dough onto a lined baking sheet. Press the cookies together with your hands, if the dough is crumbling. Bake for 18-20 minutes and remove from the oven when very barely browned on the bottom, taking care not to brown the tops of the cookies.
Transfer the cookies to a wire rack. While the cookies cool, combine the powdered sugar, syrups, cream, and vanilla in a small bowl. Whisk until smooth. Add more cream or milk, just a few drops at a time, as needed to thin the glaze. Drizzle the glaze over the cooled cookies. Store in an airtight container. Enjoy!
Notes
The humidity where you live will affect how much cream is needed in this recipe. I've found that sometimes 1/3 cup is enough and other times a tablespoon or two additional liquid is needed to make the dough come together. It should be somewhat dry and loose (similar to biscuit dough) and you should be able to press it together with your hands.