"Pillars of Creation" caused by photoionization feedback (He, Ricotti & Geen, 2019). The thermal pressure resulting from photoionization heating efficiently disperses the parent cloud. I show that photoionization feedback is efficient at dispersing dense molecular clouds before the onset of supernova explosions. Based on a set of simulations of collapsing molecular clouds extending a wide range of masses and densities, I find a strong linear correlation between the star formation timescale regulated by photoionization feedback, $t_{\rm SF}$, and the cloud crossing time of HII-fronts, $t_{\rm cr}$, typically at a speed of $c_s \sim 7$ km/s. I find the following empirical relation: the ratio of $t_{\rm SF}$ to the free-fall time, $t_{\rm ff} = (\pi/2) (R/v_{\rm esc})$, roughly equals $v_{\rm esc}/2.6$ km/s, where $v_{\rm esc}$ is the escape velocity at the cloud surface. We also find that the star formation efficiency per free-fall time scales with the density to the second power and approaches ~20 percent in very dense scenarios. Molecular clouds with escape velocities above ~7 km/s and high density (> 1000 cm$^{-3}$) deposit over 15 percent of the gas into stars and form gravitationally bound star clusters which appears to be globular cluster progenitors.