Contrary to the popular belief and TRP assumptions, morphological masculinity is not significantly correlated with attractiveness:

The relationship between masculinity and attractiveness was assessed in two samples of male faces. Most previous research has assessed masculinity either with subjective ratings or with simple anatomical measures. Here, we used geometric morphometric techniques to assess facial masculinity, generating a morphological masculinity measure based on a discriminant function that correctly classified >96% faces as male or female. When assessed using this measure, there was no relationship between morphological masculinity and rated attractiveness. In contrast, skin colour – a fluctuating, condition-dependent cue – was a significant predictor of attractiveness.

However, it seems like attractive faces are perceived to be masculine even when they aren't.

In contrast to the results in section 3.1, there was a significant positive correlation between rated masculinity and attractiveness in both samples when using subjective measures (Pearson correlations, sample 1: r(20) = .513, p = .021, sample 2: r(75) = .248, p = .032, see table 2). This finding indicates that subjective judgments of masculinity are based on factors other than just morphological masculinity.

Source: Does Masculinity Matter? The Contribution of Masculine Face Shape to Male Attractiveness in Humans