Generated by SassMeister.com.

SassMeister-input-HTML.html

        <p class="gradient-test">Donec ullamcorper nulla non metus auctor frinitemlla. Sed posuere consect etur est at lobortis. Aenean eu leo quam. Pellentesque ornare sem lacinia quam venenatis vestibulum. Aenean eu leo quam. Pellentesque ornare sem lacinia quam venenatis vestibulum. Praesent commodo cursus magna, vel scelerisque nisl consectetur et. Vestibulum id ligula porta felis euismod semper.</p>

SassMeister-input.sass

// ----
// Sass (v3.3.0.rc.2)
// Compass (v1.0.0.alpha.17)
// ----

=my-mixin($class-name, $tal: left, $width: 33.333%)
  .#{$class-name}
    text-align: $tal
    // First content thing
    @content

  .#{$class-name}__item
    width: $width
    // I want a second @content or somethign to add 
    // styles to the this module class
    @content
  

+my-mixin(spammy)
  // this get's applied to both, duh, but is there something
  // that might solve this and allow additional properties for
  // the module class?
  background: orange

// Extending doesn't work, obviously. Extending content would
// be nice though… hmm…
.spammy__item
  @extend .spammy__item
  content: "wtf am I doing"

SassMeister-output.css

.spammy {
  text-align: left;
  background: orange;
}

.spammy__item {
  width: 33.333%;
  background: orange;
}

.spammy__item {
  content: "wtf am I doing";
}

SassMeister-rendered.html

        <p class="gradient-test">Donec ullamcorper nulla non metus auctor frinitemlla. Sed posuere consect etur est at lobortis. Aenean eu leo quam. Pellentesque ornare sem lacinia quam venenatis vestibulum. Aenean eu leo quam. Pellentesque ornare sem lacinia quam venenatis vestibulum. Praesent commodo cursus magna, vel scelerisque nisl consectetur et. Vestibulum id ligula porta felis euismod semper.</p>