Start by heating a saucepan over medium heat, then sprinkle the sugar evenly into the pan. Watch as it begins to melt and turn a golden amber color, swirling gently to promote even caramelization. This process takes about 5-7 minutes and fills your kitchen with a warm caramel aroma.
Once the sugar is fully melted and has a rich amber hue, add in the butter carefully—it will bubble vigorously. Stir continuously until the butter is fully incorporated and the caramel becomes smooth, about 1-2 minutes.
Slowly pour in the heavy cream while stirring. The mixture will bubble up again, so pour steadily and stir until the caramel is thickened and glossy. Remove from heat and let it cool slightly—this helps the caramel set up just enough without becoming too firm.
Transfer the warm caramel to the blender, then add the whole milk and heavy cream for smooth blending. Toss in the ice cubes afterward, so they don’t start melting immediately, maintaining the slushie’s icy texture.
Blend on high speed until the mixture is thick, frosty, and velvety, usually about 30-45 seconds. Check for smoothness; if needed, blend a bit longer to achieve a uniform, slushie consistency.
Pour the caramel slushie into glasses, swirling gently to showcase the rich caramel streaks throughout. Serve immediately for the best icy texture.
