A method of fabricating an airfoil assembly comprising: fabricating a first core including a first plurality of ribs defining a first plurality of mircrocircuit cooling passages of a completed airfoil assembly, wherein the first core is fabricated from a first material; fabricating a second core including a second plurality of ribs defining a second plurality of cooling passages of the completed airfoil assembly, wherein the second plurality of ribs includes a plurality of standoffs, wherein the second core is fabricated from a second material different than the first material; assembling the first core and the second core into a core assembly such that the plurality of standoffs set a spacing between the first plurality of ribs and the second plurality of ribs to define a spacing between the first plurality of cooling passages and the second plurality of passages of the completed airfoil, wherein the first core includes fingers extending upward for defining openings through a tip of the completed airfoil assembly, the fingers being offset from the first core within the airfoil a distance in a direction between the suction and pressure sides of the airfoil so as to allow for the openings to be supplied by the microcircuit cooling passages defined by the first core while being disposed radially over the second plurality of larger cooling passages defined by the second core portion , the tip of the completed airfoil including a recessed portion and the openings are defined in the recessed portion; molding the airfoil assembly around the core assembly ; and removing the core assembly including the first core and the second core . fabricating a first core including a first plurality of ribs defining a first plurality of mircrocircuit cooling passages of a completed airfoil assembly, wherein the first core is fabricated from a first material; fabricating a second core including a second plurality of ribs defining a second plurality of cooling passages of the completed airfoil assembly, wherein the second plurality of ribs includes a plurality of standoffs, wherein the second core is fabricated from a second material different than the first material; assembling the first core and the second core into a core assembly such that the plurality of standoffs set a spacing between the first plurality of ribs and the second plurality of ribs to define a spacing between the first plurality of cooling passages and the second plurality of passages of the completed airfoil, wherein the first core includes fingers extending upward for defining openings through a tip of the completed airfoil assembly, the fingers being offset from the first core within the airfoil a distance in a direction between the suction and pressure sides of the airfoil so as to allow for the openings to be supplied by the microcircuit cooling passages defined by the first core while being disposed radially over the second plurality of larger cooling passages defined by the second core portion , the tip of the completed airfoil including a recessed portion and the openings are defined in the recessed portion; molding the airfoil assembly around the core assembly ; and removing the core assembly including the first core and the second core . <EOS>