In a dry skillet over medium-low heat, add the almonds, and broken cinnamon sticks. Lightly toast just until the almonds start to turn golden brown and fragrant, about 4 to 5 minutes, stirring occasionally to make sure the almonds don’t burn. We don’t want to completely toast them or they’ll overpower the flavor. Remove from heat.
In a large bowl, mix together the rice, almonds and cinnamon sticks, then pour in 3 cups of hot water. Set aside and let rest for 4 to 6 hours. Make sure the water is hot to the touch but isn’t boiling. We don’t want to cook the rice.
Make the strawberry puree by combining the strawberries, 1 cup of water, and 1 tablespoon of sugar in a small saucepan under medium-low heat. Bring to a simmer, then let cook for 4 minutes, stirring occasionally until the strawberries have softened. Set aside to cool, then transfer to a blender, and blend until smooth.
Set the strawberry puree aside until the rice is done steeping.
After the rice has steeped for 4-6 hours, pour the rice/cinnamon mixture (liquid and all) into a blender, and blend for 30 seconds, then strain through a fine-mesh coffee filter (to ensure your horchata isn’t chalky or grainy) into a pitcher.
Stir in the strawberry puree, then add in the remaining 3 cups of water, condensed milk, and vanilla extract. Let chill for two hours, then give it a stir before pouring, then serve over ice.