Bake for 30 minutes, stirring + flipping every 10 minutes with a metal spatula.
Remove from oven and sprinkle with chocolate chips while the granola is still warm.
Wait a minute and stir (no longer). This helps the chocolate melt just slightly and as you break up the granola the slightly melted chocolate will help form clusters.
Cool completely before adding any other add-ins. Say chocolate covered espresso beans or chocolate covered almonds.