Method

• Preheat the oven to 350°F (175°C). Spread the finely chopped pecans in a single layer on a small baking sheet. Toast for approximately 5–7 minutes, stirring once, until fragrant and slightly darker in color. Transfer the pecans to a plate and let them cool completely before adding them to the dough. Warm nuts can soften the butter and affect the dough's consistency. Keep the oven temperature at 350°F (175°C) if you plan to bake the cookies after chilling.
• In a large mixing bowl, beat the softened butter and sifted powdered sugar with an electric mixer on medium speed for approximately 2 minutes. The mixture should be smooth, creamy, and slightly lighter in color. Avoid beating it until excessively fluffy. Incorporating too much air can make shortbread puff and spread more during baking.
• Add the vanilla extract to the butter mixture: Mix briefly on low speed until incorporated, scraping down the sides of the bowl with a rubber spatula. The mixture should remain thick and creamy.
• In a separate bowl, whisk together the flour and fine salt. Add the flour mixture to the butter mixture in two additions, mixing on low speed after each addition. Stop mixing when the dough forms soft, slightly crumbly clumps and no large pockets of dry flour remain. Shortbread dough is naturally firmer and less sticky than many other cookie doughs. Avoid adding liquid simply because it looks crumbly.
• Add the completely cooled toasted pecans and plain toffee bits. Fold them into the dough with a rubber spatula until evenly distributed. If the mixture seems crumbly, gently press a small handful together. It should hold its shape when compressed. Avoid prolonged mixing, which can make the finished cookies tougher.
• Divide the dough into two equal portions: Place each portion on a sheet of plastic wrap and shape it into a log approximately 8 inches long and 2 inches in diameter. Roll each log gently against the work surface to create an even cylindrical shape. Press in any loose pieces of pecan or toffee that protrude excessively. Wrap each log tightly in plastic wrap.
• Refrigerate the wrapped dough logs for at least 1 hour, or until firm enough to slice without flattening. For the roundest cookies, rotate the logs occasionally during the first part of chilling so the bottoms do not become noticeably flat. If the logs become extremely hard after extended refrigeration, let them stand at room temperature for approximately 5–10 minutes before slicing.
• Line two large rimmed baking sheets with parchment paper. If the oven has been turned off, preheat it again to 350°F (175°C). Position the oven racks in the upper and lower thirds. Remove the chilled dough logs from the refrigerator and unwrap them.
• Using a sharp knife, cut each log into 16 rounds approximately ½ inch thick, creating 32 cookies in total. Rotate the log slightly after every few cuts to help maintain its round shape. If a cookie cracks or crumbles around a piece of pecan or toffee, gently press it back together with your fingers.
• Place 16 cookie rounds on each prepared baking sheet, leaving approximately 1½ inches between them. These shortbread cookies should spread only slightly, but a little space allows hot air to circulate and promotes even baking. If the dough becomes very soft while slicing, refrigerate the arranged cookies briefly before placing them in the oven.
• Bake both sheets for approximately 14–16 minutes, switching their rack positions and rotating them halfway through baking. The cookies should have lightly golden edges and pale golden bottoms, while the centers remain relatively light. Watch carefully during the final few minutes. Toffee pieces near the edges may turn darker than the surrounding dough. Avoid waiting for the entire surface to become golden brown, as this can result in dry, overbaked shortbread.
• Remove the baking sheets from the oven and let the cookies rest on them for approximately 5 minutes. The cookies will be delicate immediately after baking but will become firmer as they cool. Carefully transfer them to wire cooling racks and let them cool completely for another 25 minutes.
• Once the cookies are completely cool, lightly dust them with the optional powdered sugar. Use a fine-mesh sieve to distribute the sugar evenly. For a cleaner appearance that highlights the pecans and toffee pieces, leave the cookies plain.
• Arrange the cooled Toffee Pecan Shortbread Cookies on a serving plate or package them in an airtight container. Serve with coffee, tea, hot chocolate, or as part of a holiday cookie assortment. Their buttery flavor and crisp, delicate texture become more noticeable once the cookies have cooled completely.