Cooling apparatuses, cooled electronic modules, and methods of fabrication are provided which facilitate heat transfer from one or more electronic components to a coolant. The cooling apparatus includes a coolant-cooled heat sink with a thermally conductive structure having a coolant-carrying compartment including a varying cross-sectional coolant flow area through which coolant flows in a direction substantially parallel to a main heat transfer surface of the structure coupled to the electronic component(s). The coolant-cooled heat sink includes a coolant inlet and a coolant outlet in fluid communication with the coolant-carrying compartment, and the coolant flow area of the coolant-carrying compartment decreases, at least in part, in a direction of coolant flow through the coolant-carrying compartment. The decreasing coolant flow area facilitates an increasing effective heat transfer coefficient between the main heat transfer surface and the coolant by, at least in part, accelerating the coolant flow within the coolant-carrying compartment.