Preheat oven to 325°F. Add graham crackers, brown sugar, cinnamon, and salt to a food processor, and pulse into fine crumbs.
Melt butter, and add crumb mixture to the melted butter. Stir to combine until completely coated.
Dump crumb mixture into an ungreased 9 inch glass pie plate. Press the crumb mixture firmly into the pie plate only halfway up the sides of the pan.
Bake for 10-12 minutes until golden brown and fragrant. Cool completely on a wire rack before filling.
Using a handheld electric mixer (or stand mixer), beat softened cream cheese until smooth. Scrape down the bowl, then slowly add sweetened condensed milk while beating. Then add vanilla until combined. Scrape the bowl again, then add the powdered sugar, and beat until smooth and silky.
Pour filling into the cooled crust. Spread evenly to the edges, and swirl the top. Cover pie, and refrigerate overnight until firm (minimum 6 hours).
Prepare topping no more than 15-30 minutes before serving. Cut strawberries into quarters or halves lengthwise, and place them in a bowl.
Add vanilla, cinnamon, and agave, and gently toss to evenly and thoroughly coat the strawberries. Cover and refrigerate for 15 to 30 minutes.
Cut pie, and place each slice on a plate. Spoon strawberry topping on each individual slice.