Converting a draft script from bash to Make - makefile

Question

I like to have a script which will fill in front matter when I write new blog posts. In the past, I did this using Bash as seen below.
#!/bin/bash
# Set some variables
export site_path=~/Documents/Blog
drafts_path=~/Documents/Blog/_drafts
title="$1"
# Create the filename
title=$(awk '{print tolower($0)}' <<<"$title")
filename="$title.markdown"
file_path="$drafts_path/$filename"
echo "File path: $file_path"
# Create the file, Add metadata fields
cat >"$file_path" <<EOL
---
title: "$title"
layout: post
tags:
---
EOL
# Open the file in BBEdit
bbedit "$file_path"
exit 0
While not the nicest code, it does the job. As I've moved my other scripts to using Make, I'd like to do the same here. Here the section of my Makefile where I've defined the draft rule. I think I've escaped all variables, but it still will not run. Can someone explain where I may be going wrong?
SITE_PATH=~/Documents/Blog \
DRAFTS_PATH=~/Documents/Blog/_drafts \
TITLE="$$1" \
TITLE="$$(awk '{print tolower($$0)}' <<<"$$TITLE")" \
FILENAME="$$TITLE.markdown" \
FILE_PATH="${DRAFTS_PATH}/$$FILENAME" \
FILE_PATH="$${FILE_PATH}" \
cat >"$${FILE_PATH}" <<EOL \
--- \
title: "$$title" \
layout: post \
tags: \
--- \
EOL \
# Open the file in BBEdit
bbedit "$${FILE_PATH}" \
exit 0
Update: For reference, the complete Makefile is here where draft simply executes the original shell script.