Preheat the oven to 350. Whisk the flour, muffin mix, sugar, cranberries, pecans and lemon zest in a large bowl. Make a well in the center and place the eggs and vanilla in it. Break up the eggs with a fork, then stir them into the dry ingredients to make a stiff dough.
Knead the dough a few times on a lightly floured work surface until smooth; shape into a 12-by-3-inch log. Place on a baking sheet lined with parchment paper and bake until golden, about 30 minutes. Cool on a wire rack.
Using a serrated knife, cut the log crosswise on an angle into thin slices (about 1/4-inch thick). Place the slices on the parchment-lined baking sheet and bake until golden, about 20 more minutes. Cool completely.