Heat oven to 350°F. Finely chop half the pecans, and leave remaining ones in halves; set aside.
In an electric mixer fitted with the paddle attachment, combine baking powder, flour, sugar, and salt. In a bowl, beat eggs, yolks, and vanilla. Add to dry ingredients; mix on medium low until sticky dough is formed. Stir in pecans, cranberries, and zest.
Turn dough out onto well-floured board; sprinkle with flour, and knead slightly. Shape into 9-by-3 1/2-inch logs. Transfer to prepared baking sheet. Bake until golden brown, 25 to 30 minutes. Let cool enough to handle, about 10 minutes. Reduce oven to 275°F.
On cutting board, cut logs on diagonal into 1/2-inch-thick slices. Return pieces cut side down to baking sheet. Bake until lightly toasted, about 20 minutes. Turn over. Bake until slightly dry, about 20 minutes. Cool on wire rack. Store in airtight container.
