Stir in brown sugar, butter, and 1/2 cup almond milk in a saucepan.
Bring to a boil, reduce heat to medium-low, and simmer for 5-8 minutes, stirring occasionally, until obtaining a dark caramel-like color.
In a bowl, whisk cornstarch together with 1 cup of almond milk until fully dissolved (with no lumps).
Stir in the rest of the milk and add to the brown sugar mixture.
Return to a boil, reduce heat to medium-low, and simmer for about 5-8 minutes, stirring constantly, until pudding thickens.
Remove pan from heat and stir in almond extract. Pour pudding into ramekins, let cool, cover, and refrigerate until set.
Serve with a generous dollop of Reddi-wip® Almond Non-dairy whipped topping and garnish with toasted almond slices, if desired.