Preheat an oven to 190 degrees C. Sift the flour, bicarb soda and salt together in a bowl.
In a large bowl, beat together the butter, white and brown sugars and vanilla essence with an electric mixer until the mixture is creamy and well blended.
Beat in eggs one at a time then gradually beat in the flour just until the mixture makes a soft dough. Stir in the pecans, rolled oats and cranberries then drop by heaping spoonfuls onto ungreased baking trays.
Bake in the preheated oven until the biscuits are set and the edges are slightly brown, 10 to 12 minutes. Let the biscuits cool for 1 minute on baking trays before removing to wire racks to finish cooling. Glaze biscuits while still a little warm.
To make the glaze:
Place the icing sugar and orange juice in a microwave-safe bowl and stir to dissolve the sugar. Stir in the orange zest and butter then microwave on medium power until the butter melts and the mixture is warm, about 30 seconds. Stir the warm glaze until smooth and drizzle over biscuits.