Make the Cookies: Combine the pecans and 1/4 cup of the sugar in a food processor and process until fine crumbs, but before the nuts start to release their oils. Set aside.

In the bowl of a stand mixer, beat together the butter and the remaining 1/2 cup sugar until light and fluffy and pale in color, about 4 minutes. Beat in the vanilla, then use a spatula to scrape the sides of the bowl.

Whisk together the flour and both salts, then add to the mixer, along with the reserved pecan/sugar mixture. Beat on low until the dough just comes together, about 30 seconds. Scrape the sides and bottom of the bowl and mix for another 10 seconds.

Lay a large piece of plastic wrap on the counter and dump the dough on top. Work the dough together, then pat into an 8x8-inch square, using a bench scraper to square off the sides. Wrap tightly in the plastic wrap and refrigerate for at least 30 minutes, up to 3 days.

Heat the oven to 350ºF. Line 3 13x18-inch baking sheets with parchment paper.

Cut the dough into 6 even strips. Working with one strip at a time, roll the dough back and forth into a log. Cut the log into 8 equal pieces, keeping the log together, then re-rolling to regain the cylinder shape. Place the pieces, cut side down, on the baking sheet, spacing evenly and putting 20 pieces on a sheet. Use your finger or the end of a mixing spoon to make an indentation in the center of each cookie.

Baking one pan at a time, place the pan in the oven and bake for 8 minutes. Remove from the oven and use the end of a wooden spoon to tap down the indentation on each cookie. Rotate the sheet and place back in the oven for another 4 to 6 minutes. The cookies will have set around the edges when they are ready and they will have slight cracks on top. Leave the cookies on the pan to cool. Repeat with the remaining cookies.

While the cookies are baking, start the praline. In a large pot, melt the butter over medium heat. Add the maple syrup, both sugars, vanilla and both salts and stir to combine. Cook until it comes to a boil, then let it boil for 3 minutes to thicken. Pour in the cream and stir to combine. Let the mixture continue to cook until it coats the back of a spoon. Stir in the pecans.

While the cookies are still warm, use a spoon to spoon some of the praline into the center of each cookie. Refrigerate until set, about 30 minutes.

Cookies can be stored in an airtight container at room temperature for up to 3 days or in the refrigerator for a week.