In a saucepan, combine the orange liqueur, sugar, water, cloves, and cinnamon stick and bring to a boil. Stir to dissolve the sugar. Add the cranberries. Reduce the heat to a simmer and cook until the berries burst, about 8 minutes. Remove from the heat and let the berries cool in the liquid. Remove the cinnamon stick and cloves and discard.
Preheat the oven to 350 degrees F. Lightly grease a 9 1/4 by 5 1/4 by 2 1/2-inch loaf pan.
In a mixer bowl, using the mixer on high speed (or using a hand mixer), cream the sugar and butter. Add the eggs and beat until light and fluffy. Into a bowl, sift together the flour, baking soda, cinnamon, and salt. In a small bowl, combine the buttermilk and orange juice. Alternately add the dry ingredients and buttermilk mixture to the creamed butter, beating after the addition of each. Fold in the reserved cranberry mixture, pecans, orange zest and vanilla. Pour into the prepared loaf pan. Bake until a tester comes out clean, 55 to 60 minutes.
Turn out onto a wire rack to cool. Serve warm or at room temperature. (Can be made ahead. Wrap tightly and store at room temperature 1 day or freeze for up to 2 weeks.)